


i 





Class 
Book. 









Q 



Copyright M". 



COPYRIGHT DEPOSIT. 



A TEXT BOOK 



ON 



WELDING AND 
CUTTING METALS 



BY THE 



Oxyacetylene Process 



WITH SIXTY-FOUR ILLUSTRATIONS 

THIRD EDITION-REVISED 

Copyrighted 1915 
By C. H. BURROWS 



VULCAN PROCESS CO. 

MINNEAPOLIS. MINN. 






PREFACE TO THIRD I^UITKJX. 



It is diiU' ;i short time since the second eihtion was issued, 
and it is yratifyinii' to find that the stipply is nearly exliatised. 
I'here are many mechanics and atitot^enons welders who desire 
short, clear and ])ractical instructions on the snhject of oxy- 
acetylene welding- and it is the ])ur])ose of this book to fill thi'^ 
demaiul. 

A com])rehensi ve treatise on this subject would necessarily 
includi' much technical material that would be useless to the prac- 
tical man who wishes to ac(|naint himself with onl\ enough 
theor\ to thoroUjU^hh' master the performance of his duties, and 
for this reason we have excluded nearl\- everything of a strictly 
technical nature. 

The C"hai>ters on chemistrv. physics and metals are ot the 
most elementarv natiu'e. and cover in the plainest lani^uaj^e 
only the subjects that are vital to the welders information. At 
the same time the\' are suliicientlv explicit to i^ive him a tlu)rouL;h 
workiuL^- knowledi^e of the subjects that ])ertain t i his work. 

In compiling; these ])ai4es we ha\e cousulted the works on 
the .Manufacture and I'rojjerties of Iron and Steel, liy 11. 11. 
(,"ami)l)ell. U'he .\Ietallnri;\ of Iron and Steel, by I'.radley 
Stoui^hton, and Autogenous Welding, by ( iranzon and Rosem- 
berg : and some of the text relating to generators and welding 
has been c<indensed from pa])ers which we contributed to a few 
of the leading magazines. 

C. 11. lUirrows. 



MAR 18 1915 

©CI,A39ri81 



Ill 



CONTENTS 

Story of \'ulcan, lAhthology) 

Cha]:)ter 1. The use of the (i.\\-acet\lene flame 
Chai:)ter 2. Chemistr_\- 



.VI I 

... 4 
11 



Tlie Elements', Table of Chemical Symliols, and .Vtomic Weislits. 
Chemical Affinity. The Atomic Theory, Valence. Reaction, ('(un- 
bustion. Flame. Oxygen. Hydrogen. Nitrogen, Calcium Carbide. 
.\c('tylene. 

Chajiter 3. I Musics 25 

Pneumatics, Boyles Law. Heat. The Calorie, The British Tliermal 
Unit, Temperature, Centigrade and Fahrenheit, Table comparing 
degrees Centigrade and F;ihrenheit. Exi)ansion, Table of Coeffi- 
cients of Kx]iansion witli instructions on its use, 

(Hiapter 4. Melals and tluMi" !'n)])crtics 35 



Tlic Ferrous (irou)i. Cast Iron. Malleable Iron. Wrought Iron. 
.Steel. Tlic Mlister I'mccss. Cop].(.r, Brass. .Vluminuin, .\lloys. 

Chapter 5. .\eelylene ('cneralors 

Dri]. T\ pi\ Floodini;- T.\ pe. Carbide to Water Type. S.decting .\ 
(iellerator. 

C'haiUer (). ( ).\y-.\celyleiie W'eldini; and I'ntlini;- 

Torches 

Low Pressure. FTigli Pressure. Cutting Torches. 



Chapter 7. Ke^idatdrs and Indicalnrs 

Tlii'ir ni.iuipulation. 

I'hapter S. The \ nlcan .\nt( malic Acetxlene ( ieneratnr 

Its ojieration and manipulation. 

Cliapter 9. ( )])eralin;4 IMants 

Ciuupi'essed (i.as Plants, Ceueraloi- Plants. Pipe installation. 

(_'ha])tei- 10. WTldiiiL^ \\f>(\> and I'duxes 

The tlicory <if tluNcs. Hods and tluxes for all iuiri)Oses. 

Cdiajjler 11. Weldini.^ 



44 

50 

58 
(A 



( )\y acetylene. Preheating. Cast Iron, ihilleable Iron, Steel, 
Aluminum. Copiier. Brass, .\lloys, Gold and Silver. 

(/hapler 12. C 'ultin-' 

Theory. I'sing the torch. The \'nlcan torch. Instructions on 
.\ssenibling. 

(diai)ler 13. I'.iMler and Sheet .\lttal WTrk 



Prelu'ating. Repair \V(:irk. Corroded Mud Drums. Inserting new 
])lates, Cutting door holes, man holes, etc., Patclies. Welding in 
flues, Fabricatiut;- new woi-K, Sanction of P.oiler Insurance 
Companies. 

(_diapter 14, Carluui llniMiin^' 

Theory, Cleaning .\uto Cylinders. 

■ Useful Infdi'niatinn and d'ahles 



89 

110 

118 

126 
128 



IV 

TABLES. 

Page 

I. Elements, their symbols ami atomic weights 12 

II. Weights of gases 21 

III. Average yield of gas from \arious grades of carbide 2;> 

IV. Heat conductivity of different metals 'M 

V. Coefficients of expansion 3',i 

VI. Melting temperature of metals 'M) 

VII. Loss of pressure in pipes "U 

VIII. Loss of pressure by valves 71 

IX. Cost of oxyacetyleiie cutting 114 

X. Cost of cutting with oxygen jet 128 

XL. Cost of welding with oxyacetylene torch 12S 

XII. C^iiaiitity of gas in cylinders 121) 

XIII. Variation of pressure in cylinders 129 

XIV. Comparison degrees Centigrade and Fahrenheit 130 

XV. Weight of oxygen di'ums 130 

XVI. Consumption of gas — and cost of oxyacetylene welding 131 



LIST OF ILLLUSTRATIONS. 
Figure Page 

1 Broken locomoti\e cylinder 2 

2 Same cylinder after welding 3 

3 Building in gear teeth 5 

4 Broken crank shaft 8 

5 Same shaft after welding 

(5 Repairing broken pump case 10 

7 Corner in chemical laboratory 15 

S Phases of combustion 17 

9 Oxygen plant 18 

10 Generator room in electrolytic oxygen plant 19 

1 1 Electrolytic cells 20 

12 High ]iressure pump for gas compression 29 

14 Typical carbide to water generator 4() 

15 Modern oxyacetylene welding torch 50 

16 Oxyacetylene torch 53 

17 Straight line torch 53 

18 Oxyacetylene cutting torch 54 

19 Vulcan combination cutting and welding torch 55 

20 Torch for welding machines 57 

21 Automatic acetylene regulator 58 

22 Automatic Oxvsen Regulator 59 



23 Oxyaeetylene welding plant 60 

30 Vulcan automatic, acetylene generator 61 

31 Vulcan generator welding plant 63 

32 Interior of Vulcan generator 65 

33 Vulcun portable generator plant 67 

23 Welding table 75 

24 Combination welding table 76 

25 Oxygen valve on oxygen drum slowly 78 

26 Removable base for oxygen drum 79 

27 Portable plant using dissolved acetylene 82 

28 Portable generator plant 84 

29 Convenient time card 86 

34-35 Practical method of beveling thin pieces 90 

36 Method of beveling thick pieces 71 

37-38 Illustrating economy of beveling on both sides 91 

39-40 Effects of expansion and contraction 92 

41 The melting rod should not 97 

42 Circular movement of torch for work of medium thickness 9<S 

43 Side to side movement of the torch for heavier welds 99 

44 Position of torch for filling holes 100 

45 Crank shaft on V blocks i)repared for welding 107 

46 Auto cylinder prepaiH^d for welding 108 

47 Cutting machine 113 

48 Cutting macd) ine 114 

49 Cutting floor beams 115 

50 Cutting old boiler 116 

51 Cutting old boiler 117 

53 I Examples ot l"]xpansi()ii 121 

54 I 

55 Overcoming effects of expansion 121 

56 Deformation caused l)y expansion 122 

57 
58 
59 

60 \ Good and bad 

61 /Examples of inepared joints 123 

62 i 

63 1 

64 / 

65 Carbon burner at work 127 

66 Fabricating a l)Osh jacket 120 



/ 



\ I 




VULCAN 



Vll 



VULCAX 

The Roman ( iod (^t Fire 

In <il<len davs when Jupiter, tlie ( iod of all dther (iods. <h\elt 
on tlie celebrated mountain (^lym])ns. and ])resided over the 
ancient Romans: when XeiJtune dominated over the sea. and the 
heautifnl Diana, with her maidens, cared for all the wild animai> 
of the forest; there came to tlie familv of Jupiter and his wife. 
Juno, a little son whom the\ called \ ulcan. 

Little \ nlcan possessed i^reat ])(iwers and ability, but he was 
11(11 a handsome child and bis mother |uno, who was disap])ointed 
in not ha\in^' a more beautiful son to i.;race the home of the 
( iods, threw him down from I leaven. The infant (iod. falling; 
into the sea, was ri-scut'd and adopted bv Thetis, who kept him 
until he was nine years old. and then restored him to bis ])arents. 

hwen in his youth, the little (iod displayetl wt)nderful abilit\ 
at the tor_i;e and all metallic handicrafts ; and Jtipi^^^' recoi^iiiziu!.' 
this wonderful ability, made him the (iod of Fire. Tie late^" 
erected forj^es and work sho])s in which he emploved wonderfid 
one-eyed giants, called tlie Cyclops, to assist liim. In these shops 
he fabricated many i;real metal works, and one of his ])rin- 
t"i])al duties was to Foi-l^c thunder bolts for his father Jupitor. 
.Some claim his shops were on Mount Ktiia, where he used the 
heat of the volcano to work his forties. 

\ iilcan not only bad the ability to make the hottest tires and 
fort^e the most ditticult metal objects; but he was artistic b\ na- 
ure ; so when Jupiter wished to ])rovide the earth with the first 
mortal woman, \ ulcan fashioned lier out of clay, and the (lods 
animated the statue, ."^o his wonderful work is handed down to 
the present da\ in the i,''race and beauty of om* women. 

In honor of this Roman (iod. we have dedicated this book and 
named our jjrocess. wdiich develoi)s the hottest flame known, and 
causes the hardest metals to flow like wax. to X'ulcnn the (iod 
of Mre and Tatron < f all metallic handicraft! 

\ idcan I 'rocess ("o. 



WELDING AND CUTTING METALS 

BY THE 

OXYACETYLENE PROCESS 



OXY-ACETYLENE ^VELD1NG AND CUTTING 




FIG. 1. 
HHOKKX LOCOMOTIVE CYLINDER. 



This illustration shows the cylimler after the edges of the fracture 
liad been chipped for welding. 

The bar across the front and a similar bar across the rear was used to 
support a temporary grate, upon which the preheating fire was built. 



OXY-ACETYLEXE WELDIXG AXD CUTTIXG 




FKi. -2. 
LOCOMOTIVE CVEIXDKR AFTKK WKLDIXG. 



This illustrates the same cvliiuler shown in Fig. 1, with a new east 
iron piece welded in the fracture. Ordinarily the old piece is used to 
make the mend, hut in th's case the old piece had been destroyed by 
repeated attempts tu weld it in with thermit. 



4 OXY-ACKTVLKNF, WKl.DI.Nii AND (TTTINC 

CHAPTER I. 
THJ-: USE OF THl-: OXY-ACETYLENE FLAME. 

The oxy-acetylene welding and cutting torch has become 
so popular in the last few years, that almost every issue of 
the trade papers in any liranch of work contains interesting 
accounts of new successes in the use of tliis powerful tool. 
The first ai)])licatio!i of the process, to coniniercial use, dates 
back to 1903, and its rapid growth in popularity is due to the 
ease and economy with wdiich its intense heat is applied to 
any of the metal trades, to join two pieces by welding, or 
separate them bv cutting without the stroke of a hammer. 

A notable example of the saving that may be effected by 
using this process is in the event of repairing a broken loco- 
motive cylinder shown in Fig. i. This cylinder had a piece 
broken out of the wall including a j)ortion of the flange. 
Previous attempts to weld this piece in place by other method?^ 
had proven disastrous, and resulted in making the fracture 
larger. The oxv-acetylene process was then brought into use, 
and in less than a day's time a new piece was welded in as 
shown in Fig. 2. The cylinder was rebored, drilled, and the 
job finished without removing it from the locomotive. A 
great saving in this case is credited to the fact that the loco- 
motive was put back into service in a comparatively short 
time, and the repairs were made without dismantling. The 
durability of this work is illustrated in fact that this cylinder 
was welded July loth, 1910, and is still in successful operation. 

Very often small pieces of a machine are broken off and 
lost, and in consequence the whole machine is out of use. In 
such cases it is not always necessary to have the missing piece 
with which to make rejiairs. but the missing portion may be 
built on with similar material melted from the welding rod. 
A good example of cases where this process is appliable is in 
building new teeth into a broken gear or sprocket wheel, build- 
ing u]) lugs or adding new material to ])arts that are badly worn. 
There are innumerable instances where the addition of a little 
metal will save much expense and long delays, and in the opera- 



TlIK ISK OF Till-; OXV ACKTVLKXK FLAME 




FKJ. ;•.. 
HriLDi.xd IN (ii:.\i; TKirrii. 

Ill this process tho old teeth aic not i('i|uiicil to iiial^e thi' iiieml, but 
new material is built u]> to form a new todtli. 

tion of contractors who are remote fi-oin tlieir base of su])|)lies. 
this sometimes amounts to (|uile an item. 

I^irge shipyards, railroad shops, contracting eng^ineers, 
as well as the smaller institutions, machine sho])s, boiler shops, 
foundries, i^aras^es and 'blacksmiths, all find this powerful flame 
indispensable for sure, quick and economical results. In proof 
of this statement it is well to cite experiments made at dif- 
ferent times, and in ditiercnt places by two of our foremost 
railway systems. These experiments were very carefully con- 
<lucted through a ])erio(l of 14 days to ascertain to a certainty 



6 OX Y- ACETYLENE WELDING AND CUTTING 

the exact economic value of this process. Every item of cost 
was carefully checked against the records of former methods, 
and the results showed an average saving of $155 a day, for 
each day the test continued. 

This immense daily saving was made possible by having 
plenty of work on which to use the process, but the condi- 
tions were far from ideal, and it is safe to say, had the condi- 
tions been more favorable this figure could have been nearlv 
doubled. 

Another field where this tool is finding great favor is in 
cutting iron and steel structures, heavy plates, door holes 01 
man holes in boilers, and in cutting up the wreckage of steel 
structures which have been destroyed by fire or wind. A re- 
cent incident where the o.xy-acetylene torch proved to be valu- 
able for this work, occurred in the harbor at Duluth where 
the wind destroyed several large steel docks. It is difficult 
to imagine the bewildering entanglement of steel bars, beams 
and angles all piled up in a huge irregular mass. Heavy steel 
members were twisted and interlaced with smaller members 
in such a way that they could not be removed without cutting, 
and to cut them with a sharp edge tool was next to impossible. 
The only tool suitable for this work was the oxy-acetylene 
cutting torch, and it was employed with very economic ad- 
vantage. 

Another occasion where this torch became conspicuous 
was in cutting up the wreckage of a steel freight steamer, 
which was sunk on the east coast about a year ago. The 
vessel had broken up and lay in pieces in about 30 feet of 
water. The pieces weighing 25 to 40 ton were a shapeless 
mass, with the plates, beams, and members bent and crumpled. 
The plates forming the shell of the boat were about Ys in. 
thick at the to]) and on the sides, but on the bottom they 
were much heavier. The rivets could not be removed, since 
in many cases the flanges of angles and pieces of plates were 
bent over against them, preventing access to their heads. The 
condition of the steel was such that the expense of ordinary 
hand cutting would have been prohibitive, and the wreckage 



THE USE OF THE OXYACETYLENE FLAME 7 

would have been a total loss had the oxy-acetylene torch not 
been available. 

An idea may be formed of the speed and ease with which 
steel plates can l)e cut by this process from the following- 
figures : 

Plates 1/2 inch thick — 30 inches per niiinite. 
Plates I inch thick — 20 inches per minute. 
Plates 1].^ inch thick — 16 inches per minute. 
Plates 2 inch thick — 12 inches per minute. 

This information is ta])ulated in the back of the book. 

To obtain a comparison, in time and cost, between cutting 
by hand in the usual way, and doing- the same work with 
the oxy-acetylene cutting torch, careful observations were 
made and recorded, as outlined. Cutting a full door patch 
for boiler by the old method required six hours time for a 
boiler maker and his helper at a cost of $4.04. Doing the 
same job with the cutting torch required nine minutes time 
of one man and cost 25c. Cutting a side sheet and door sheet 
by the old method, required eighteen hours for a boiler maker 
and his helper, and cost $12.15. Doing the same work with 
the cutting torch required one-half hours time of one man and 
cost 83c. 

These two comparisons were not selected to favor one 
cause or the other, but were taken at random from a list of 
many similar operations. 



OXV-ACl-yrVLKNK WKLDIXG AND (TTTTNG 




Tlie illiistriition sIkiws ;i 
rcjiaratory to woldiii";. 



fk;. \. 
BK'OKKN (K'ANK SHAFT. 

x iiicli crank shaft hciiij: hrouglit into shop 



'J'lio illustration 1m^-. 4 shows a crank shaft six inches in 
diameter and eleven feet long. It was a member in a three 
cylinder 100 IT. P. producer gas engine, belonging to a single 
unit electric light plant, and was broken square oft" through 
one of the arms, totally disabling the entire plant. It was 
taken to a wielding shop and with the oxy-acetylene torch the 
complete job was welded and ready to deliver in less than 
twenty-four hours, at a cost of about $26.00. A detail of this 
cost is as follows : 

8 hours welding time @ 35c — $2.80 

817 ft. Oxygen @ 02c — 16.34 

812 ft. Acetylene @ 00.8c — 6.49 

50 lbs. Charcoal @ oic — .50 

After cooling, the weld was found to be perfectly homo- 
geneous in texture, void of fire-scale, or oxidation, and ma- 
chined freely. This crank shaft has since been in heavy service 
for a year or more and is giving perfect satisfaction. 



Till-: isK OF TiiK ().\^' AC l•:'^^"l. i:\i-; fi.a.mk 




CK'ANK SHAFT AF'I'KK' \Vi:M)l\(i. 

The charct)al itemized in cost was used tor preheatini;' pur- 
poses. Tlie little white cross iudicates the ])lace wliere the weld 
was uiade. 



10 



OXY-ACETYLKNK WELDING AND CUTTING 




FIG. 6. 
REPAIETNG BKOKEN IT.Ml' CASE BY AUTOGENOUS WELDING. 

In this illustration the }>Iato whidi is shown bolted temporarily in the 
openinir of the pump case, was used as a grating to support the preheating 
fire. 



11 
CHAPTER 11. 

CHEMISTRY. 

Origin. The practical part of this science existed previous- 
to the theoretical ; and may be traced to Tubal Cain, the father 
worker of metals, but by degrees, as men began to think they 
also began to observe and theorize. 

Thinking men saw that a gross earthy matter, such as iron 
ore, became changed, by fire, into a hard metallic substance 
like iron, and upon these observations was built the most per- 
fectly systematized and exact science of the day. 

The Elements: — In the earth are millions of chemical com- 
pounds which are mixed together to form the air. the water^ 
the minerals or animal and vegetable life, and all of these com- 
pounds are capable of being separated into more simple sub- 
stances called "elements." For example water may be separ- 
ated into hydrogen and oxygen. Acetylene gas may be sep- 
arated into the simpler substances, carbon and hydrogen. In 
these examples the water and acetylene are chemical com- 
pounds, but the hydrogen, oxygen and carbon are elements 
and are not capable of being separated into more simple sub- 
stances. These elements may be separated into atoms, but 
all the atoms of any one element are alike in size and weight, 
and are composed of the same single substance as the element 
which it composed. Then we may say that an element is a single, 
simple substance, zcliich is dissimilar to, and incapable of bei)ig 
separated into, any other substance. 

Chemical Symbols. — The earlier chemists employed the 
signs of the planets to represent the metals; thus, silver was 
the moon, hence the expression "silvery moon," and the term 
••lunar caustic" for silver nitrate. In the modern science each 
of the elements are represented by one or two initial letters 
called "svmbols" taken from the Latin name of the element. 
The symbol for iron is Fe, because the Latin name of iron 
is ferrum. That for oxygen is O ; for hydrogen is H ; for car- 
bon is C; and for calcium is Ca. 



12 OXY-ACETYLKNK WKLUIXG AND CUTTING 

A table of about one-half of the known elements is arranged 
below showing- their symbols and atomic weights. 

TAHLH 1. 
Elements, Their Symbols and Atomic Weights. 

Arsenic As 7.") ManjiaiR'sc Mn 55 

Barium - Ha 1.57.4 Molvhdenuiu Mo 96 

Bismuth Bi 2(is Nickel Ni 59 

Boron - B 11 .Nitroj^en N 14 

Calcium Ca 40 O.vvireii O 16 

Carbon C 12 i*lios|)horus P 31 

Chlorine CI 35.5 I'otassium K 39 

Chromium Cr 52 Silicon Si 28.4 

Cobalt Co 59 Silver A^ 108 

Copper Cu 63.6 Sodium Na 23 

Fluorine F 19 Sulphur S 32 

Gold - Au 197 Tin Sn 118.5 

Hydrogen H 1 ritanium Ti 48 

Iodine 1 127 Tungsten Wo 184 

Irone Fe 5ti X'anadium V 51 

Lead Pb 207 Zinc , Zti 65.4 

Magnesium Mg 24 

Chemical XofatioJi. — Ihe ])rinciples upon which the modern 
chemical notation is founded, is that each symbol indicates 
one or more atoms of the element it represents, thus C, C2, C27 
indicate respectively, one. two and twenty-seven atoms of car- 
bon. Two symbols, placed side by side signifies that they are 
in close chemical union ; thus CO signifies a compound con- 
taining an atom of carbon and an atom of oxygen. L2 H2 
signifies that two atoms of carbon are in chemical union with 
two atoms of hydrogen, forming one molecule of acetylene. 
When symbols are separated by the sign -f- it signifies that 
the atoms thus separated are not in chemical union to form 
one substance ; but are mingled and still exist as separate sub- 
stances, thus C2 H2 -J- O2 signifies that one molecule of acety- 
lene is mixed with two atoms of oxygen. A number placed 
on left of a group of symbols signifies that the whole group, 
as far as the next comma or plus -|-. is to be multiplied by it; 
thus 2 CO signifies that one atom of carbon and one atom of 
oxygen are combined to form one molecule of carbon monoxide 
and that two of those molecules are represented. The expres- 
sion H2 -\- 2 CO, signifies that two atoms of hydrogen are 



cllK.MlSTm' 1?. 

mingled with two molecules of carbon monoxide. llie sign = 
signifies a reaction or the result of mingling the atoms or 
molecules of different substances; thus, C2 H2 -{- O2 = TT2 + 
2 CO signifies that if one molecule of acetylene becomes 
mingled witli two atoms of oxygen, there will be a chemical 
union in which two atoms of carbon unite with two atoui- 
oxvgen, forming two molecules of carbon monoxide and liber- 
ating the two atoms of hydrogen, which become mingled with 
the monoxide in an uncombined state. 

L'liriiiica! .Iffiiiity. — The attraction that causes elements to 
unite and form new substances, like water, acetylene or car- 
bon monoxide, and afterwards holds them together, is called 
chemical affinity. Some elements apparentK- have no affinity 
for each other, while others have a tremendous affinity. Some 
elements have an affinity for each other under certain in- 
fltiences, and will tinite forming- new sul)stances, but ttnder 
other influences this affinitv mav be destroyed and the sub- 
stances separated again into their original elements. Some 
of the more common influences which may eft'ect the affinitv 
of elements are heat, pressure and an electric current. 

To start chemical union it is sometimes only necessary to 
mix two substances together and they will unite and form 
a new substance. In this instance the elements are held to- 
gether by affinity. If this substance be mingled with another 
element under a different influence it may become separated 
and one of its elements unite with the newly added element. 
Take for instance acetvlene, which is com])ose(l of two atom> 
of hydrogen and two atoms of carbon held together by af- 
finity. Under ordinary conditions this union is stable and 
the acetylene may be mixed with oxygen without forming 
any new substance; but if heat or j)ressure is applied the car- 
bon will leave the hydrogen and unite with the oxygen. The 
result in case of applied pressure w(ndd l)e an explosion. 

llir .Itoiiiir Tlu'orx. — b"r(tm the foregoing it is observed 
that the uniou of atoms to form new substances is represented 
by a group of s\mbols, to which are attached various sign< 



14 OXY- ACETYLENE WELDING AND CUTTING 

and figures. This group of symbols and figures is called a 
■chemical formula. Let us study these formulas a little farther. 
Take for instance C2 H2, from the table of atomic weights 
we find the atomic weight of C = 12, and H ^ i ; then form 
this formula C2 H2 we may derive four thoughts : 

(i) the formula represents 1 molecule of acetylene. 

(2) one molecule of acetylene contains two atoms of carbon 
and two atoms of hydrogen. 

(3) one molecule of acetylene is composed of 24 parts by 
weight of carbon, and 2 parts by weight of hydrogen. 

(4) by weight, acetylene contains 26 parts. 

If the formula and atomic weights are known, the percentage 
of the composition ma\ be calculated as follows : 

C = 2 X 12 = 24 or 24 parts by weight of carbon 

H = 2 X I = 2 or 2 parts by weight of hydrogen. 

26 parts bv weight in acetylene 

— = .923 or 92 ^yt carbon by weight 
26 



-= .o7(n)2 or 8', bvdrogen bv weight 
26 

J'aleiicc. — Atoms differ with respect to the number of atoms of 
other elements with which they will combine. This diflference 
in combining power is indicated by the term valence. 

Hie valence of an element is the niiinber of hydrogen atoms 
with zvhieJi its atom, will niiite, or replace. 

In water Ii2 O we find that one atom of oxygen wall unite 
with two atoms of hydrogen, therefore we say the valence of 
oxygen is II. The valence of carbon is IV. and of calcium is II. 
This means that one atom of carbon will unite with or replace 
four atoms of hydrogen, and an atom of calcium will unite with 
or replace two atoms of hydrogen. 

The application of valence is useful in writing formulas and 



CHEMISTRY 



15 



determinin.u' reactions. Thus, knowing- that the valence of car- 
bon is IV, we know each atom of carbon will miite with fotir 
atoms of hydrogen, and since the valence of oxygen is II each 
atom of oxygen will replace two atoms of hydrogen. Then in 
the reaction C2 H2 + O2 = H2 + 2 CO, as stated on page 14, 
we know the tinal H2 will unite with one more atom of oxygen 
and the final 2 CO will unite with two more atoms of oxygen. 

The complete reaction may be expressed as follows: 
C2 H2 + O2 = H2 + 2CO 
H2 4-0 = H2 O = one molecule water 
2 CO -|- O2 = 2 (CO2) = two molecules carbon dioxide 




FIG. 7. 
CORNER IN CHEMICAT. T..\BORATOK'V. 



16 OXY-ACETVLK.XI-: WKLDIXC; AND Cl'TTlXG 

Reaction. — The combination of elements to form a new snb- 
stance is called reaction. The term expresses a chemical union 
in which the resulting- substance has ])r()])erties ditterent from the 
elements which compose it. 

If the elements are minified without chemical union, there 
is said to be no reaction. Thus if finely i^round sul]:)hur be mixed 
with finely ground iron no new ])ro]^erties are produced, and 
we say no reaction has taken place, but if we heat the mixture 
a chemical action takes ])lace in which the elements unite to form 
a new' substance. Then we say there has been a reaction. 

When reactions produce heat. the\" have chemical energy. 
which can be transferred into other forms of work. Xot all 
reactions j^nxluce heat, biU some are accompanied bv a consump- 
tion of heat, and therefore use up energy, or rather they trans- 
form energy into chemical work. This heat energy is not lost 
for we can get it back by reversing the action. 

Coinhitstioii. — Combustion is a reaction in \vhich a fuel (com- 
bustible) unites with oxygen and produces heat. There are sev- 
eral elements that will react with oxygen in this way. l/'oremost 
among these are carbon, hydrogen and iron. When there is )usi 
the rig-ht amount of both oxygen and combustible to cause reac- 
tion, w'e have perfect combustion: but if there is an excess of 
either element, we have incomplete combustion. Incomplete con^- 
bustion always results in loss of heat. 

Flame. — When reaction is very ra])id. the heat developed may 
cause the gaseous elements to glow like white hot iron. These 
glowing gases are flame. I-dame has three distinct i)arts: the 
central or non-luminous part, where there is no combustion, but 
where the carbon l)egins to sei:)arate from the hydrogen; the 
second or luminous part, where the carbon is for a moment free 
and heated to a white heat ; and the exterior i)art, which is the 
hottest, and where combusion is complete. The foregoing is true 
with the ordinary flame where the oxygen is derived from the 
atmosphere and combustion takes on the exterior: but in the 
oxy-acetylene flame the oxygen is supplied in a pure state and 
mingled with the combustilile before it is ejected from the torch. 
This causes very rapid reaction and intense heat, and in this 



CHKMTSTRY 



17 



case, since the reaction is at the interior the hottest part is at tlie 
point of .i;:reatest ilhimination. It is easy now to understand of 
what iin])ortance is tlie form of the Inirner. and how we max 
mochfv it accordin^h- as we want Ht^ht or Iteat. If we wish Hght 
tlie carhon nuist he protected for a moment while it is in the 
ii'lowinij- state, hnt not long- enotigh for it to pass off itnconstimed. 
If. on the contrary, heat is desired, the carlron timst he linrned as 
rapidly as possible. 




FIG. s. 
PHASKS OF CO^rBT'STIOX IX OX V Ai ■1•:T^■ LKM-: FLAMK. 

Independent of the iiarts described on page 17, the oxy-acety- 
lene flame is divided into two very distinguishable parts, the 
inner flame, where the oxygen. su])i)lied by the torch, reacts with 
the carbon in the acet\"lene. producing carbon monoxide, and 
setting the h\(lrogen free; and the outer dame where the carbon 
iuon(»xide and Indrogen reacts with the oxygen supplied b\- the 
atmosi)herc. The inner tlanie is of a dazzling white, but the 
outer flame has a bluish tinge, due to the coiubusticju of hydro- 
gen, --urrounded by a yellow tlame due to the combustion of car- 
bon monoxide. The temperature, taken at the extremity of the 
white jet. is very nmch higher than that of an\ other flame, and 
is calculated to be ()3oo degrees F. 

To attain this lemperature without waste of gases, the torch 
must be constructed on highh scientific i)rinci])les. The size of 
the openings, the mixing chamber. i)ressures of gases, are all 
factors to be considered in its design. 



Ox^"GE^'. 

( )xygen is an odorless, colorless, tasteless gas. It is mingled 
with nitrogen in the air. and ccimliined with hydrogen in water. It 
is united with nearly all the minerals in their native state, and is 
the most abundant element know 11 to us. At ordinar\ temuera- 



18 



OXY-ACETYLENE WELDING AND CUTTING 



tures it forms few chemical reactions, but when heated, is one of 
the most active elements, vigorously reacting- with hy- 
drogen and carbon, as well as their compounds in the form of 
gases. 

When oxygen reacts with an element the product is called 
an oxide, and the process is said to be oxidation. When iron is 
red hot it oxidizes very rapidly. The welder should therefore 
adjust his torch to procure a perfectly neutral flame, with just 
enough oxygen to consume the acetylene. 

Oxygen is prepared in a variety of ways, giving as great a 
variety in percentage of purity. For commercial purposes it may 
be made from chlorate of potash and manganese dioxide in the 
proportions of lOO pounds of the chlorate of potash to 13 pounds 
of the manganese dioxide. These two chemicals are first thor- 
oughly mixed, and then placed in a retort and heated. This lib- 
erates the oxygen, which passes off through washers to storage 
tanks. The cost of producing oxygen in this way, depends on the 
price of chemicals. With chlorate of potash at 93/2C per pound 
and manganese dioxide at 2;)4c per pound, the cost would aver- 
age 4c per cubic foot, including cartage, shop expense, etc. 




FIG. 9. 
OXYGEN PLAN. 

Usiii" CivstalliziNl Cliloiate of Potash and Manganese Dioxide. 



CHEMISTRY 



19 



Oxygen from .llr. — Oxygen may also be extracted from air. 
If, by means of comliined pressnre and cold, air be converted into 
a liquid, its two components may be separated by centrifugal 
force, or else tbe nitrogen may be allowed to evaporate leaving 
tlie liquid oxygen behind. No chemical processes are necessary 
for this separation because the elements are not combined. 




(;kxki{atoij wuum 



FIG. 10. 
\ Kl.llC'rii'Ol.VTIC O.WCKX 1"1..\.\T. 



Oxygen by Electrolysis of Jl'ater. — Oxygen and hydrogen 
are liberated when an electric current is passed through acidu- 
lated water. The apparatus first used for this ])ur|)ose consisted 
of a vessel containing water and having suspended therein, two 
test tubes with their open end submerged. Positive and nega- 
tive electrodes were placed just beneath the opening in the tubes, 
and when an electric current was caused to flow through the 
water between the electrodes, oxygen was liberated at the nega- 
tive pole, and hydrogen at the positive pole. These gases ascended 
and were gathered in the tubes. 



20 



OXY-ACKTYLKXK WKl.DlMi AND crTTlXG 



Although the prochiction of oxygen and hydrogen, hy the 
electrolysis (vf water, is one of the oldest electrochemical ex|)en- 
ments, it was not nntil recent years that the i)rc)cess was made 
economicalK' practical. There was considerahle difificnlty in 
developing an apparatus that would operate successfully in prac- 
tice. One of the hardest conditions to meet was the necessity of 
ahsolute safety. The ])ro1)lem has now heen worked out satisfac- 
torily so that large scale electrolysis of water is on a solid indus- 
trial hasis. Oxygen made hy this process is most pure and hest 
adapted to oxy-acet\ lene w elding. 




FIG. n. 

ELECTKOI.VTIC CELLS YOU (i KN KKATIXO OXYGKX. 



Hydrogen. 

Hydrogen is a colorless, tasteless, odorless gas. and the light- 
est substance known. By weight it forms ii per cent of water. 
and 8 per cent of acetylene. Hydrogen also exists in all living 
forms. It has a high chemical affinity for oxygen, and bnrn-^ 



CIIKMISTKV 



21 



with it at a temperature of about 4100 degrees F. When usef.' 
in the cutting torch with oxygen it is a very satisfactory fuel fo^ 
cutting the ferrous metals. Hydrogen is obtained in its purest 
form by the electrolysis of water. 

XlTROGEX. 

Nitrogen is a colorless, tasteless, odorless gas, foruiing "j 
l)er cent of air. It is of no Ijenetit to tlie nxy-acetvleue welder, jti 
fact it is a detriment since it does not supi)ort combustion but 
absorbs heat from the flame. 



TAHLK II. 
WEIGHTS OF GASES. 



„ ^ At 32° F and 14.7 lbs. pressure | 


of Specific 
Gas 1 Gravity 


Volume 
of one pound 1 
cubic foot ' 


Weight 

of one 

cubic foot 


Oxygen 1.104 | 11.2056 

Air 1. 1 12.388 

Hydrogen .069 178.891 

Nitrogen .972 12.7226 

Acetylene .. .91 13.6126 


.08925 

.08073 

.00559 

.0786 

.07346 



Calcium Cakiudi-: 

Calcium is the metal that exists iu lime. Its symbol is Ca. 
Carbon, a solid but not a metal, occurs in the earth in crystallized 
form as graphite and as diamonds. It is also the fuel element 
in coal. The symbol for Carbon is C. 

Calcium Carbide (Ca C2) is a compound of Calcium and 
Carbon in the proportions of 62 ])er cent calcium to 38 per cent 
carbon which combine to form a hard crystalline substance of a 
dark gray color, *Iii describing the manufacture of calcium car- 
bide it is well for the reader to remember that the materials 
employed are among the most refactory ones which we know. 
Lime is so infusible that it is frequently employed for the material 
of crucibles in which the highest melting metals arc fused, and 

*Froni hullt'tin of the ilepartiiuMit of .-lii'iiiistry. I'ciiiisylvauiii. State 
Oollefro. 



22 OXY-ACETYLENK WELDING AND CUTTING 

for pencils in the calcium light, because it is capable of with- 
standing extremely high temperatures. Carbon is the material 
employed in the manufacture of arc lights, and other electric 
appliances for the same reason. Yet in the manufacture of car- 
bide these two most refractory substances are forced into com- 
bination with each other. 

It is the excessively high temperature attainable in the mod- 
ern electric furnace, five to seven thousand degrees Fahrenheit, 
which alone accomplishes the combination of these elements to 
form calcium carbide. 

The electric arc being formed in the furnace, a thoroughly 
incorporated mixture of coke and lime in the right proportion is 
introduced. The change which takes place is 

Ca O -f 3 C = Ca C2 -f CO 

which means thai tifty-six pounds of lime, and thirty-six of coke 
luake 64 pounds of carbide, and liberate twenty-eight of carbon 
monoxide, a gas which escapes or is burned at the mouth of the 
furnace. Thus, for each ])ound of carbide made, there is con- 
sumed a pound and a half of a mixture which is something like 
seven-twelfths lime with five-twelfths coke. 

Granted pure material, there is formed an ingot of very pure 
carbide, surrounded by a crust of less pure product because par- 
tially unconverted. 

In breaking up, packing and shipping the carbide, this poorer 
crust is rejected. At first impure materials were employed for 
the manufacture of carbide, but this resulted in an inferior grade, 
which in turn yielded an impure gas, so that at the present time 
it is everywhere recognized as essential, that only first class ma- 
terials should be used. 

It is customary to use lime that is 99 per cent pure, and coke 
of low ash. Both must contain as little sulphur and phosphorus as 
possible. 

Carbide decomposes with water in accordance with the fol- 
lowing chemical equation : 

Ca C2 -f- 2 H2 O = C2 H2 -f Ca (OH) 2 

A pound of absolutely pure carbide will yield ^y'j feet of 



CHEMISTRY 23 

acetylene, but absi)lnte purity is not a practical commercial possi- 
bility. In practice good carbide may be expected to produce 
never less than four cubic ft. and rarely more than five cubic ft. 
of acetylene gas per pound of carbide. The table on page 2^ gives 
the gas yield of various grades carWde. 

TABLE III. 
TIIK AY K RAGE YIELD OF GAS. 

From the Xnrious (Jrados of Carbido. 

Grade 3l-.x2 414 cubic feet 

Grade 2 x \i> ^ 4i/^ cubic feet 

Grade li4x % 41/^ cubic feet 

Grade %xl/]2 _ 4 cubic feet 

Grade Electrolite - 4 cubic feet 

Calcium Carbide is a safe substance to store or transport 
under proper conditions. It cannot explode, take fire, or other- 
wise do harm, miless exi)Osed to moisture. In that event the 
water in the moisture will slowly liberate acetylene which in the 
presence of flame, will ignite. 

ACETYLEXE. 

-Xcetylene is a colorless, tasteless gas, possessed of a peculiar 
penetrating odor. It is a compound of two atoms of carbon to two 
atoms of hydrogen, and is known by the formula C2 H2. Being 
composed of these two elements only, it belongs to a class of 
compounds known as hydro-carbons. All hydro-carbons are 
combustible and acetylene will explode when only 3>^ per cent 
is mixed with air. Its ignition point is lower than coal gas, 
being about 900 degrees F. against iioo degrees required to 
ignite coal gas. It burns in air with a brilliant but smoky flame, 
uniting with the oxygen of the air. in the following proportions. 

2 Cj II2 -f 502 = 4 CO2 + 2 II2 O 

Acetylene is an endothcrmic compound. In its formation 
heat is absorbed, and there resides in the acetylene molecules the 
power of spontaneously decomposing and liberating this heat if 
subjected to temperatures or pressure beyond the capacity of its 



24 oxy-acetylp:ne welding and cutting 

nnstaple nature to withstand. Acetylene is decomposed into its 
constituent elements at a critical temperature of approximatel)- 
1400 (leQTees F., or at the critical pressure of two atmosphere? 
(29.4 pounds) at which pressure it becomes dangerous. 

.Acetylene, without the mixture of air or oxygen, at ordinary 
pressures, is not explosive in any sense, except as referred to 
?.bove. 

When acetylene is used in the blow torch it combines with 
oxygen in equal volumes and liberates much heat. The tempera- 
ture of the oxy-acetylene flame, taken at the extremit}- of the 
white jet. is very nuich higher than that of any other flame. It 
is calculated to be 6300 degrees F. In all cases the white jet of 
the oxy-acetylene flame can melt lime, the melting point of which 
is estimated at 5432 degrees. 



CHAPTER HI. 

PHYSICS. 

P)icitii'atics. — Pneumatics is that branch of mechanics which 
treats of the properties of ^ases and air. 

It was supposed In- the ancients that air was inponderable. 
that it weighed nothino-, and it was not until the year 1650 that 
it was proven that air really had weight. .\ cubic foot' of air 
under ordinary conditions, weighs about eight onediundredths 
of a pound. Since air has weight it is evident that the enormous 
quantity of air that constitutes the atmosphere must exert con- 
siderable i)ressure on the earth. By experiment and calculation 
this pressure has been determined to be 14.7 jx.nnds ])er square 
inch. 

In the strictest sense of the word, air is not a gas. but is a 
mixture of gases and consists of about 23 parts oxvgen and yy 
parts nitrogen, by weight; or 21 parts oxygen and 79 parts nitro- 
gen, by volume. Its physical characteristics are the same as 
the gases, and in this respect it is classified among them. 

The most striking feature concerning gases is that, no matter 
how small the (piantity ma\ be they will always fill the vessels 
which contain them, and if the temperature of the confined gas 
remains the same, the pressure and volume will always vary the 
same way. The law which exjjresses this is called I'.oyle's Law, 
and is as follows: 

Boyle s Laxv. — The temperature remaining constant the volume 
of a given quantity of gas varies inversely as the pressure. 

The meaning of this is : I f the size of the containing vessel is 
dnuinished to /. or >^ of its former volume, the pressure of the 
gas will be increased to 2 or 3 times its original pressure. It also 
means that if the size of the contaiiung vessel is increased to 2 
or 3 times its original volume, the pressure will dinunish to >4 
or Yi of the former pressure. 

In these and the following statements the reader should not 
confuse the w^ords volume and quantity. The volume will corre- 
spond with the cubic capacity of the vessel, while the quantity 
will represent the amount of air or gas contained in the vessel 
under pressure. 



26 OXY- ACETYLENE WELDTXG AND CUTTING 

Suppose a steel drum is such a size that it will measure ex- 
actly 3 cubic feet. If it is open to the air it is evident the drum 
will contain 3 cubic feet of air at atmospheric pressure. Then if 
twice as much air, or 6 feet is put into the drum, the pressure 
will be doubled to 29.4 pounds, and if one hundred times as 
much air or 300 feet is put into the drum the pressure will be 
raised 100 times and become 1470 pounds. Xow if half of this 
air, or 150 feet, is drawn out, the pressure will be reduced to one- 
half of 1470 pounds and become 735 pounds. 

As a necessary consequence of Boyle's law, it may be stated 
that, iJic quantify of gas in a given si:;e drum, varies directly as 
the pressure. 

Knowing the quantity of gas a drum will contain under cer- 
tain pressure, the quantity for any other pressure may be calcu- 
lated by the following sinn)lc formula in which 

A ^ the nominal rated pressure 

B = pressure of gas in drum 

C = capacity of drum under A pressure 

X = contents of drum in cubic feet of gas 

Ti CB _ 
Then — . — — X 
A 

Expressing this formula in words, we have the rule. 

Multiply the rated capacity of the drum by the pressure of 
gas in the dru)n and divide by the nominal rated pressure to Und 
the contents of the drum. 

Suppose an oxygen drum contains 200 feet of gas at 1800 
pounds pressure, and after being used for sometime the pressure 
has diminished to 700 pounds. If we wished to learn the quan- 
tity of gas still remaining in the drum, the calculation would be 
as below. 

200 X 700 77 

1800 ^^loO^^^' 

In all that has been said before, it has been stated that the 



PHYSICS 27 

temperature was constant ; the reason for this wih now be ex- 
plained. Suppose a definite quantity of air at 32 degrees F. be 
placed in a cylinder with a movable piston and that this piston is 
weighted to cause the air to be at a constant uniform pressure. 
If the temperature of the air within the cylinder be raised to 
33 degrees F. it will be found that the piston has raised a cer- 
tain amount, consequently the volume has increased while the 
pressure remained the same. If more heat is applied and the 
temperature raised to 34 degrees F. it will be found the piston 
has raised again, and that every increase in temperature will 
cause a corresponding increase in volume. The law that expresses 
this change is called (iay-Lusac's Law. and is expressed as fol- 
lows : 

Gav Lnsac's Lazv. — // tlic pressure remains constant every 
increase of temperature of 1 dc'^ree F. produces, in a i^iven 
quantitx of i^as, an expansion of ^'.j of its volume at 32 degrees 
F. 

If the pressure remains constant it will be found that every 
decrease of i degree F. will cause a decrease of .'..; of the vol- 
ume at 32 degrees F. 

According to the modern and now generally accepted theory 
of heat, the atoms and molecules of all bodies are in an incessant 
state of vibration. The vibratory movement in gases is faster 
than in liquids, and in liquids it is faster than in solids. Any 
increase in heat increases the vibrations, and a decrease in heat 
decreases them. From calculation and experiment, it has been 
concluded that all vibration ceases at a temperature of 460 degrees 
below zero. This point is called absolute zero, and all tempera- 
tures reckoned from this point are called absolute temperatures. 

When the word temperatu.re alone is used the meaning is the 
same as ordinarily applied, but when absolute temperature is 
specified, 460 degrees F. must be added to the temperature. The 
absolute temperature corresponding to 32 degrees F. is 460 -f- 
32 = 492 dgrees F. 

In calculating the effect of an increasing or decreasing tem- 
perature, upon the volume or pressure of gases, the temperature 
is reckoned from absolute /.ero. 



28 OXY- ACETYLENE WELDING AND CUTTING 

Suppose a steel drum is charged with 200 cubic feet of gas at 
1800 pounds pressure, and at a temperature of 68 degrees F. ; 
and subsequently the temperature is raised to too degrees F. The 
increase in pressure may be calculated by the following formula 
in which 

A = the nominal ratetl j)ressure of the drum at 68 degrees 
Fahrenheit. 

T = the absolute temi)erature of 68 degrees F. 

t = absolute temperature of gas in drums 

E = pressure of gas at t temperature 

t 
Then A = E 



PHYSICS 



2S) 




FIG. 12. 
HIGH PRESSURE PUMP FOR GAS COMPRESSION. 



Three cylinder liydraulie iiuinp liavinji; eapacity to compress 12 cubic 
feet of {ras per minute from 1,.")()0 poiiii'ls to 2,200 pounds pressure per 
square inch. 



30 OXY-ACETYLENE WELDING AND CUTTING 

Expressing this formula in ^vords we have the rule. Divide 
the absolute teiiiperature of the gas in the drums by the abso- 
lute temperature of 68 degrees F., and multiply the quotient by 
the nominal rated pressure of the drum, to find the pressure due 
to a change in temperature. 

This final ])ressnre is computed as shown. 

4()0 + loo =^*^^ J Q(3 

460 + 68 = S2^ 

1.06 X 1800 = 1908 = final pressure 

Heat. — As to the exact nature of heat, scientists dift'or. but 
all modern thinkers and investigators agree that heat is a form of 
ejiergv. ft is not proj>osed here to enter into the different theories 
regarding heat, but this nmch of the generally accepted theory is 
given to make clear the ]:)rincii)les which are to follow. 

To avoid possible misunderstanding the attention of the read- 
er is first directed to the difference between the quantity and 
intensity of heat. This difference is easier explained by a series 
of illustrative statements. 

'J'he same amount or quantity of heat may be delivered to 
<iqual amounts of different materials without having the same 
sensible effect. 

Equal weights of different substances, having the same tem- 
perature may be placed in an oven and be subjected to the same 
heat for the same length of time, and their final temperature will 
be considerablv different, although each has received the same 
quantity of heat. 

Then it is clear that the same quantity of heat will not raise 
the same weight of different materials to the same temperature. 

Reversing this experiment we find that if e(|nal weights of dif- 
ferent substances be heated to the same temperature and plunged 
into vessels containing like quantities of water at like tempera- 
tures, the water in the dift"erent vessels will not be raised to the 
same degree of temperature. 

Then it is clear that these various substances actually con- 
tained different quantities of heat at the same temperature. 



PHYSICS 31 

Uiilf of Heat. The standard with which quantities of heat are 
measured is caUed the heat unit, and represents the amount of 
heat required to raise a certain amount of water one degree in 
temperature. Different communities use the same general meth- 
ods for determinino- heat units, hut vary the amount of water to 
suit the convenience of their national standards, therefore it was 
found necessary to distinouish hetween the methods in which 
dift'erent standards arc employed. 

The British Thermal Unit. — The quantity of heat required to 
raise one pound of icater one degree TaJirenheit, is eallcd a British 
Thermal Unit. Instead of writino- out the words l*ritish Ther- 
mal unit in full it is customary to ahhreviate them P>. T. l^ 

The Calorie. — 77/r quantity of heat required to raise one 
kilogram of leafer one degree Centigrade is ealled a Calorie. 

One calorie is e(|ual to 3.96 B. T. U. 

Temperature. — The wM:)rd temperature expresses the sensible 
heat which a substance possesses, and is measured by comparison 
with some other substance havino- the same amount of sensible 
heat. For convenience and for scientific purposes, two scales oi 
comparison are employed. I'.oth scales are compared with the 
same substance at the same temperatures, the only dift'erence 
being in the graduations of the scales. These are called the 
h\ahrenheit and (Vutigrade scales. 

Thermometers. — The instrument on which these compara- 
tive scales are arranged to measure temperature is called a ther- 
mometer. The divisions of the scale are called degrees, the 
substance with which they are com])ared is water, and the tem- 
perature at which they are coni])are(l is the freezing i)oint and 
l)oiling i)oint. 

Fahrenheit. — ( )n the hahrenheit scale the freezing ])oint of 
water is marked ^J, and the boiling ])oiut _'IJ. and the interven- 
ing space divided into 180 ecpial parts called degrees. Thirty- 
two degrees are marked off on the lower end of the scale, and 
called z.ero. So in speaking of water we would say that it freezes 
at 32 degrees above zero, and boils at 212 degrees above zero. 



32 OXY-AC'KTVLKXK WKLDIXG AND CUTTING 

As many rlej:2^rees arc marked above the hoilins^' ]>(»iin (»r loelow 
zero, as are desired. 

Ccnt'r^radc. — Tii ^radualinij a Centigrade scale, the freezing 
point is marked zero, the lioihng point too. and the intervening 
space is divided into loo c(|nal degrees. 

Tt will he observed that too degrees Centigrade covers the 
same range of tem])eratnre as i8o degrees Fahrenheit, therefore, 
one degree centigrade ecpials one and eight-tenths degrees Fah- 
heit. 

Tem])eratures designated by one scale may be converted to the 
other scale b\- fonnnlas. 

When 1'^ -- degrees Fahrenheit 

and C' = degrees Centigrade 

Then 1.8 C + 32 = F. 

^' - 3-' 

Expansion. — The \-olnme of any suljstance is always changed 
when the tem]ieratnre is changed: nearly all of them expand when 
heated, and contract when cooled. This phenomenom causes the 
welder considerable trouble unless it is thoroughly understood, 
and it is well for him to give this subject much ihought and study, 
for his success depends to a great extent, on his ability to over- 
come the effects of expansion and contraction. The method of 
overcoming these effects will be treated fully under the sulyject of 
wielding. 

Suppose that a bar of iron is exactly 10 feet long at a tempera- 
ture of 50 degrees F.. if the temperature be raised to 60 degrees it 
will be found that it has lengthened a definite amount. If the 
temperature is then raised to 70 degrees it will be found to have 
lengthened exactly the same amount as before. This is true of all 
metals. Each metal will expand a certain definite amount with 
every degree increase in temperature, and when cooling they con- 
tract at precisely the same ratio ; but the dififerent metals do not 
expand with the same ratio as compared one with the other. 



rnvsics 33 

The ratio of expansion of the different metals has l)een deter- 
mined and the amount of expansion of one inch in length for one 
degree tenijierature has heen tabulated into a table called coeffi- 
cients of expansion. These seem like small amounts, but when 
the tem])eratin-es arc higli the amount of expansion is an item to lie 
considered. 

TAHLI-: A'. 
COEFFICIENTS OF KXI'AXSION FOH VAKIOFS 81BSTA.\CK8. 

Cast Iron 00000617 

Copper 00000955 

Brass 00001.037 

Silver 00()00(i90 

Bar Iron 00000(i86 

Steel (uiitenipered ) OOOOO.'OO 

Steel (teni])err<l I .I)i)(i0(i7(il' 

Aluiniimiii OOOO ]•_'!• 

Zinr 0000 k;;^ 

Tin 0000141(1 

Mercury 00003334 

Alcohof 00019259 

If a bar of cast iron 48 in. long is heated from 50 degrees F. 
to a briglit red, or 1250 degrees F, the amount it will expand may 
lie determined by formula in which, 

A = length of bar in inches 
]i = the raise in temperature 
C = coefficient of expansion 
I) = amount of expansion in inches 
Then .\. P.. C\ = D. 
Fxiiressing this formula in words wc have the rule. 

Multiply the teiii^th of the bar in inches by the number of de- 
grees raise in temperature, and multiply the prod it ct by the 
coefficient of expansion, to tind the amount of expansion in 
inches. The coefficient of expansion for cast iron is .ooocxy)!/. 
Losing this tigure and multiplying as directed we tind. 

4S X 1200 X .ooocx/il/ =^ .T,^^y)2 or Vs of an inch. 

If the bar mentioned has a section of 3 scpiare inches, and 
forms one of the arms in a gear, with one end attached to the hub 
and the other end in the rim. it will, when heated, exert a thrust of 



34 OXY-ACETLYENE WELDTXG AND CUTTING 

135 tons aoainst the rim. Ti is useless to try to resist this enor- 
mous pressure, and the only way to avoid trouble is to heat other 
portions of the gear so that all ])arts will expand toijether. In 
the parlance of the welder, this method is called prchcatini^. 

Expansion extends in all directions. If a steel plate four feet 
square is heated red liot it will become Vs of an inch wider, and 
y& of an inch longer; and when it cools it will contract the same 
amotmt. If the edges are welded solid while the plate is hot, the 
strain caused l)y contraction will amount to many tons. 

The amount of the expansion depends on the tenijierature, and 
extent of the heated ])ortion. If a bar of metal is heated in the 
center, the heat will be greatest at the point where the heat is 
applied. Some of this heat will be conducted through the bar. 
and some will radiate to the air. The distance to which it will be 
conducted through the bar depends on the speed at which the 
bar will conduct it as com])ared with the rate of radiation. 

If bars of diflerent metals are heated in the center the distance 
to which the heat will travel in the various bars will be greatest in 
the metals that are the best conductors, and since the extent of 
the heated portion is one of the determining factors of expansion 
it follows, lllicu bars of different uiclals liave heat applied to a 
limited seefioii. the best conductors i^'ill be expanded most, if 
other factors are equal. 

Silver stands foremost among the metals as a conductor of 
heat. Representing the conductivity of silver by 100 the follow- 
ing- table shows the conducting- power of some of the metals. 

TABLE TV. 
11I:AT (ONDrCTlVITY OF ])IFFi:in-:NT METALS, 

Silver 100.00 Iron 11.9 

Copper 73.6 Steel 11.6 

Gold 53.2 Lead 8.5 

Aluniiiiuin 31.3 Platinum 8.4 

Brass 23.1 Kose's Alloy 2.8 

Zinc 19.0 Bismuth '.. 1.8 

Tin 14.5 



35 



CHAPTER lA". 

METALS AXD THEIR PROPERTIES. 

The Ferrous Group. — P'nre iron is a white metal and one of 
the chemical elements, and althonq-h it is with one exception the 
commonest and most ahundant metal in the earth it never occnrs 
in natnre in the pure metallic form, but is always united with 
ox}\c:en, neither does it exist as an article of commerce, but 
appears on the market contaminated with carbon, silicon, and other 
impurities forming;" cast iron, wrou_c;^ht iron, or steel. These 
three products comprise the ferrous group, and are the largest 
manufactured product in the world. 

Iron has a chemical affinity for oxygen and carlxui. The 
former element is ruinous and destructive, but the latter element 
gives it greater strength and at the same time makes it harder 
and more brittle. So important is the influence of carbon in 
controlling the characteristics of the ferrous metals, that they 
are classified according to the amount of carbon in them. When 
melted in the ])resence of these elements it combines with them 
very rapidly, and their effect on the metal should be constantly 
borne in mind when we are using an oxy-acetylene torch, for an 
excess of either oxygen or acetylene gas will contribute oxy- 
gen or carbon to the melted metal. 

Cast Iron. — Cast iron is the most im])ure of the ferrous prod- 
ucts, and in consecpience it is com])aratively weaker, more brittle 
and melts at a lower temperature than wrought iron or steel. 
A typical exani])le of cast iron would contain about Q^^Vi per 
cent i)ure iron, 3'.. ])er cent carbon and 3 per cent other impuri- 
ties. Its tensile strength would be about 23000 pounds, and its 
melting point about 2200 degrees Fahrenheit. In solidifying 
from the molten condition to the temperature of the air it shrinks 
or shortens al)out one-eighth of an inch to every foot in length, 
or when in the solid state it shrinks about one sixty-fourth of 
an inch for every 200 degrees decrease in temperature. This 
feature re(|uires the serious consideration of the welder, for 
when cast iron is solidifying it is in its very weakest state, and 
unless this shrinkage or contraction is provided for, cracks will 
ensue. 



36 OXY-ACKTYLKXE WKT.DIXO AND ("I'TTIXG 

Another feature which may cause trouble to the welder, is 
the transfer of carbon from the graphite to the combined form 
by rapid cooling- from the molten condition. 

Carl)on is contained in soliditied cast iron in two forms, the 
g-raphitic form in which free carbon is mechanically mixed 
with the iron in little tlakes of graphite; and the combined form, 
in which the carbon is chemically united with the iron. In the 
g-raphitic form it does not efifect the hardness of iron, but in 
the combined form it will cause the iron to be hard or soft 
according to the amount contained in it. 

The welder should remember that carbon is always in the 
combined state with iron wlien the mass is in a molten condition, 
and as it cools graphite precipitates, but this cooling must be 
very slow for the change to take place since it is a very sluggish 
change and requires several seconds for its accomplishment ; 
but on the contrary if the mass is cooled rapidly this precipita- 
tion of graphite is prevented and a metal is obtained in which all 
the carbon is in the combined form, ]Moducing an iron that may 
be as brittle as glass and so hard that it cannot be machined or 
filed. This rapid cooling, which is called chilling, may be accom- 
plished by dropping- the melted iron on to a cold metal surface, 
and the resultant hard cast iron is called chilled iron. 

Malleable Cast Iron is first cast in the condition of very hard, 
brittle white cast iron. It has less carbon and silicon in its 
composition than other cast iron, and when ]>oured in the moulds 
which give it the desired shape it is rapidly cooled so that nearly 
all the carbon it contains is in the combined form. It can be 
readily understood from the preceding ]xaragraph that if this 
combined carbon can be precipitated to graphite the casting- will 
be softer, and furthermore if the size of these flakes of graphite 
can be reduced the casting will be stronger because the smaller 
are the planes of easy rupture. Being softer and stronger it may 
be bent and is called malleable. 

Eliminating and changing the carbon in white cast iron to 
make it malleable is accomplished by prolonged heat treatment 
and the process, which is called annealing, is performed after 
the iron has been cast into moulds and cooled. Thev are then 



METAL8 AND THEIR PROPERTIES 37 

cleaned and packed in iron boxes with some pulverized sub- 
stance containing- oxide of iron, such as iron ore. or mill scale, 
placed in an annealing- furnace and heated to a temperature of 
1300 degrees, and at this temperature they are kept for many 
hours. While under this heat there occurs the precipitation of 
graphite, which normally would have occurred during' solidifi- 
cation, and in the majority of cases nearly all of the combined 
carbon is changed to graphite, or eliminated by uniting' with 
the oxygen in the material used for packing. 

Under this treatment the graphite does not form in flakes 
;is in ordinary cast iron, but forms in minute particles which are 
not nearly so weakening- or embrittling' to the casting as flakes 
of graphite would be. The whole annealing jirocess requires 
about six days of continuous firing, and should not be attempted 
by persons who are not faiuiliar with the chemistry of iron, or 
who do not possess an equipment <>f furnace, iron jiacking boxes 
and packing. 

Since mallealMe iron is always cast in the form of hard white 
iron and subsequently made malleable by a process applied to its 
exterior, it follows that the change of structure is more com- 
plete at the surface giving the outside the texture of mild steel, 
while the middle ])ortion may resemble a very soft cast iron. 
It is this peculiarity which frustrates the etYorts of the amateur 
Avelder. 

Wrou^^ht Iron. — Wrought iron is almost the same as very 
low carl)on steel, its chief distinction being in the method of 
refining rather than the composition of the metal. It is niade 
by melting pig iron, steel sera]) and other ferrous materials in 
contact with iron ore. and burning out the impurities, leaving 
metallic iron. This iron is not in a melted state when finished, 
for the temperature of the furnace is not sufliciently high to 
keep it fluid after the carbon has been burned. It is in a pasty 
condition and when taken out of the furnace is a honey-comb of 
iron with each cell filled with melted lava. This honey-cc^mb is 
then squeezed and rolled until most of the slag is worked out 
and the iron frame work welded together in a crude rough bar. 
These bars, which are an intermediate i)roduct. called "'muck 



38 OXY-ACETYLENE WELDING AND CUTTING 

bars", are then cut into lengths, "piled", heated to a welding 
heat and rolled again, and after this second rolling they become 
the "merchant iron" of commerce. 

The finished bar contains less than .12 per cent carbon and 
about 1.5 per cent slag. Some think that this slag serves as a 
flux and assists in welding, but this is doubtful. It is more 
probable that the easy welding of wrought iron is due alone to 
its being low in carbon. 

Steel. — In olden times all kinds of steel, whether made in the 
crucible, in the cementation chamber or in the puddle furnace, 
contained carbon enough to make them suitable for cutting tools 
when hardened in water, and the steels that were later made in 
the Bessemer converter during the early days of its history were 
all more or less hard, much of it being used for tools ; conse- 
(luenth' the metal made in the converter was called Bessemer 
steel. 

As time went on and the cost of operation was reduced below 
that of making wrought iron, a great deal of very soft metal 
was made in the converter and open-hearth furnace. It was 
impossible to draw the line between this steel and the earliest 
products of the converter, so practical men in America and 
Europe did not try to do so, but called everything that was made 
in the converter, or in the open-hearth, or in the crucible by the 
name of steel, although the product may at times resemble 
wrought iron, and it is a fact that the method by which steel is 
made cannot be discovered by ordinary chemical analysis. 

The primitive Tubal Cain could produce a hard cutting instru 
ment w'ith no apparatus save a wrought iron bar and a pile of 
charcoal; and the natural developments have led to the conclu- 
sion that a given content of carbon will confer a greater hard- 
ness and strength, with less accompanying brittleness than any 
other element. 

There is such a widel\- varying quantity of carbon and other 
alloys in steel, accompanied by as wide a range of physical 
properties, that the subject cannot be treated in a book of this 
kind; but before leaving the subject it is well to speak of a proc- 



M1-:TALS AM) TIlKlIf I'KOI'KHTIKS 



39 



ess by which hard tool steel may he made, which has not here- 
tofore been mentioned. This is known as the ''cementation" 
or "blister" process and is undoubtedly the one used by Tubal 
Cain as mentioned in the ])recedino" paragraph. Bhster steel is 
made by placinj^' bars of \cry jnire iron in Ion*;- pots with char- 
coal and exposing- them to al)Out 1300 degrees heat. This heat 
is maintained for abcnit ten days and when the bars are removed 
thev are graded according to their carbon content which ranges 
from .5 to 1.5 i)er cent, .\lthough this process is ex])cnsive. it 
produces a ver_\- tine grade steel and it is still being used in 
Sheffield, England. 

This ])rocess is mentioned here to remind the welder, that un- 
less he uses a ])erfectl}- neutral flame, it is ]:)ossible to carbonize 
his weld, and form a scale that cannot be machined. In other 
words, if he uses more acet\lene gas than his oxygen can 
consume, the carbon of the unburned acetylene ma}- unite with 
the iron by a process somewhat similar to the blister process. 

Like other metals steel expands and contracts with heat or 
cold, and the amount of this expansion is about one sixty-fourth 
of an inch for every 250 degrees change of temperature. 

TABLK VI. 
MELTIXG TE.MKKATUKK OF .MKTALS. 



Name of Metal 


Temperature 


Name of Metal 


Temperature 
C F 


C 


F 


Tin 


223 
327 
419 


449 
621 

7Sfi 


White Cast Iron 
Gray Cast Iron... 
Jfaril Steel 


1100 2012 
1200 2192 
1400 2552 
1471 2680 
1484 2703 
1500 2730 
1776 3232 
2000 3632 
1 


Lead 


Zinc 

Aluniiuiun 


657 T^12 


Mild Steel 


Bronze .._ 

Brass 


900 
950 
961 


1652 
1742 
1762 
1949 
1949 


Nickel 


Wrought Iron ... 
Platinum 


Silver 


Copper 

Gold 


1065 
1065 


Iridium 





Copper. 

Copper is the only metal which occurs free in large, widely 
distributed clejiosits. For this reason, it was the first metal 
exclusively used by man. The copper age followed the stone 
age. The island of Cyprus was noted in the time of the Romans 



40 OXVArKTYLKXE WELDING AND CUTTING 

for its jjfi idiictioii of copper, or as it was then called, Cyprian 
brass. 

\\'e obtain the symbol C_"n. from the Latin name, Cnprum. 

The noted mines of native copper in Michigan, along' the 
south shore of Lake Superior, were extensively worked before 
Columbus discovered America. 

From them masses of copper of enormous size, one of which 
weighed nearly five hundred tons, have been obtained. These 
mines are still an important source of co])per. 

Copper has a characteristic reddish color. ( hily two of the 
connnon metals, g'old and silver, surpass it in malleabilitv and 
ductility, and it stands next to silver in as a conductor of elec- 
tricity and heat. 

The tensile strength, which is about ^^.ooo ll)>. ])er scjuare 
inch at ordinary temperatures, decreases rai)idl\ under the effect 
of heat. At 932 degrees it is only about i4(X)o lbs. per square 
inch. When cop])er is melted it oxidizes rapidly in contact with 
air, and this oxide is very soluble in the metal; it forms with it 
an alloy, which crystallizes with the mass on cooling. Melted 
copper also absorbs hydrogen and carbon monoxide which are 
present in the oxy-acetylene flame, and on cooling, the metal is 
riddled with blow holes. The effect of this oxidation and absorb- 
tion of gases, can only be overcome by the use of fluxes and 
alloys in the welding rod. 

Brass. 

Brasses are alloys of copper and zinc. They do not conduct 
heat so readily as copper, but their tensile strength when hot is 
much higher than copper. The reader will note the great dif- 
ference in melting points in the two principal elements in brass. 
Zinc melts at 786 degrees F. and vaporizes at 1684 degrees, 
while the melting point of copper is 1949 degrees, or 265 degrees 
higher than the vaporization temperature of zinc. When brass 
is melted under the direct action of the tlame, this vaporization 
of zinc is very pronounced. The copper in brass also retains 
its property of absorbtion and oxidation. So we say that the 



MKTAi^ AM) THKIK I'ROPKHTI KS 41 

melting- of brass under the action of the torch is attended In 
three distinct phenomena: Absorbtion of gases; volatihzation 
of zinc ; and oxidation. 

These difficidties are overcome by use of the proper weUUng 
rods. 

Alloys. 

*Accor<hng to tlie authoritive detinition. "a metaHc alloy is a 
substance possessing the general i)li\sical i)roperties of a metal, 
but consisting of two or more metals, or of metals with non- 
metallic bodies, in intimate mixture, solution, or combination, 
forming when melted, a homogeneous fluid. 

In plain language, this means that, when melted, the dif- 
ferent components are dissolved in one another. Metal alloy.s 
therefore, come under the general heading of solutions. In fact 
the great bulk of our alloys, are ])roduce(l by first dissolving 
the melted components and then allowing them to freeze. The 
law governing this freezing, or soliditicatioiL have only been 
known a few vears, and this new knowledge has luade great 
revolution in physical chemistry. 

In ])erfect allo\s, the solid solution bear> the same relation 
to the melted solution as a pure solid metal does to the same 
metal when melted. C"onse(|uently any solution of these metals 
will cool to the freezing point, without there being any iiuj)or- 
tant change in their rclatit)n. 

The reason that these solid solutions form in any proportion 
is that the two metals crystallize alike. It is, perhaps, a new 
thought to the reader, but it is true, that a metal forms a crystal 
when it solidifies. Furthermore, each metal has a particular, 
general shape which its crystals assume, and there is no force 
powerful enough to prevent theiu from taking this shape in 
preference to any other. 

Tiny as the crystals sometimes are, often re([uiring the highest 
powers of the microscope to reveal them, dieir crystalline forces 
are verv powerful. If. therefore, two metals do not form like 
crystals, thev cannot solidify in st)lution, i. e., in the same crystal, 

*Froin Metallurjiv of Iron mihI Steel, hv Bradley Stou<:htoii. 



42 OXY-ACETYLEXE WELUIXG AXD CUTTIXG 

but crystallization (i. e., freezing) must be accomplisbed by 
precipitation, or separation into two distinct substances." 

Tbere are a great uuniber of alloys all having" different phys- 
ical projierties, and this diiterence is sometimes due to the 
presence of an element in very small proportions. When melted 
the components of an alloy sometimes react with the flame in 
entirely different ways, and unless welding rods and flu.xes are 
used, which will compensate for this reaction, the entire struc- 
ture of the alloy may become changed. The welder should 
therefore carefully adhere to the instructions given on welding 
the various alloys. 

On the following page is given a list of alloys, their compo- 
sition and proportions. 

Sb. ^=- Antimony, Bi = Bismuth, Cu. = Copper, An. = Gold, 
Fe. = Iron, Pb. = Lead, Ni. ^Xickle, Ag. = Silver, Su. = Tin, 
Zn. = Zinc. 

TABLE OF AELOVy. 

Name of Alloy. Proportion l)y weight. 

Brass, common yellow '1 Cu, 1 Zn 

Brass, to be rolled \V1 Cu, 10 Zn, 1.5 Su 

Brass castings, common 20 Cu, 1.25 Zn, 2.5 Su 

Brass castings, hard 25 Cu, 2 Zn, 4.5 Su 

Brass, propellers 8 Cu, .5 Zn, 1 Su 

Gun metal 8 Cu, 1 Su 

Copper Hanges 9 Cu, 1 Zn, .26 Su 

Statuary 91.4 Cu, 5.53 Zn, 1.7 Su, 1.37 Pb 

German Silver _ 2 Cu, 7.9 X^i, 6.3 Zn, 6.5 Fe 

Britannia 50 Sb, 25 Su, 25 Bi 

Chinese Silver 65.1 Cu, 19.3 Zn, 13 Xi, 2.58 Ag, 12 Fe 

Chinese white copper 20.2 Cu, 12.7 Zn, 1.3 Su, 15.8 Ni 

Medals 100 Cu, 8 Zn 

Babbitt's metal 25 Su, 2 Sh, .5 Cu 

Bell metal, large „ 3 Cu, 1 Su 

Bell metal, small 4 Cu, 1 Su 

Chinese Gongs „ 40.5 Cu, 9.2 Su 

Telescope mirrors 33.3 Cu, 16.7 Su 

White metal, ordinary 3.7 Cu, 3.7 Zn, 14.2 Su, 28.4 Sb 

White metal, hard 35 Cu, 13 Zn, 2.2 Su 

Metal, expands in cooling 75 Pb, 16.7 Sb, 8.3 Bi 



METALS AND THEIR rKOPERTIES i'S- 

Aluminum. 

Althouiih aluminum is one of the most abundant and widely 
distributed metals, it never occurs free in nature. Our common 
clay consists chiefly of aluminum silicate and it has been esti- 
mated, there is enoug:h aluminum in every brick to form a coat- 
ino; an eighth of an inch thick, over its surface. Therefore it is 
not the scarcity of aluminum that contril)utes to its cost ; but the 
expense of extracting- it from the silicate. 

The only process used at present for the extraction of alum- 
inum is an electrolytic one. The apparatus consists of a rec- 
tangular ircMi box. lined with a thick layer of carbon which con- 
stitutes the cathode. The inside dimensions are about 4J/2 feet 
long', 2/2 feet wide, and 6 inches deep. Carbon rods about 3 
inches in diameter and 18 inches long-, placed in rows and sup- 
ported b}- copper bars, serve as the anodes. The process is 
made continuous by adding raw material at the top and draw- 
ing ofl: the aluminum at the bottom. The product is 99 to 99^^ 
per cent pure, and the remaining y, per cent impurities con- 
sists of traces of iron, silicon and sodium. Aluminum melts 
at 1212 degrees F., and when in the molten state it oxidizes 
rapidly and al)sorbs gases. 

The strong atifinity of aluminum for oxygen is made use of 
in the product called Thermite. 

Thcnnifc. — When a mixture of very tine particles of alum- 
inum and iron oxide (iron rust) is ignited a rapid combustion 
and very high temperature ensues. In this reaction the oxygen, 
in the iron oxide, unites with the aluminum, setting the iron 
free and liberating 4400 degrees heat. This mixture of aluminum 
and iron oxide is known by the trade name of Thermite, and 
the reaction of this substance is used to furnish heat and material 
for thermite zceldins- 



44 OXV-ACETYLENK WELDING AND CUTTING 

CHAPTER \'. 
ACETYLEXK ( iEXER ATORS. 

The function of an acetylene j^enerator, is in principle, a 
simple one. It has to bring' together the water and carbide, 
wash the gas and store it in such quantities as may be neces- 
sary. There are two general luethods of bringing the water 
and carbide together, viz.. "carbide tn water" and "water to 
carbide." Generators are therefore more fre(|uently designated 
as carbide-feed, and water feed. res])ectivel\ . Inasmuch as it 
is easier to regulate the tlow of water. 1)\- means of valves and 
other methods in common use. than to control the distribution 
of carbide, it was natural that the earlier generators should 
ojierate by s])rinkling, or dripping water onto the carbide. Eater, 
it was observed that the more rational plan was to drop suit- 
able (juantities of carbide into a large e.xcess of water. l'"rom 
these principles originated the various types of generators which 
are on the mark'et today. 

Recall the heating ])henomena of reaction. Water consists 
of hydrogen and oxygen, the dissociation of which absorbs heat. 
On the other hand, the o.xygen liberated combines with the cal- 
cium carbide, and the reaction liberates much more heat than is 
absorbed b\' the former reaction. This excess of heat is about 
<)00 B. T. I', per i)Ound of carbide; which is sufficient to raise 
the temperature of one gallon of water through 90 degrees F. 
No device or arrangement can alter the amount of heat lilierated, 
and if no cooling is effected, and the carbide is in excess pro- 
portion to the water, the temperature may become very high. 
Hig^h temperatures luay be caused when large (piantities of car- 
bide are heaped in a ciuantity of water. In the exterior of this 
heap the water reacts with the carbide rapidly and the heat 
liberated prevents it reaching the interior of the mass, except 
in very small (juantities. Arottnd the outside the carbide is 
decomposed to lime, and lime being a poor conductor, prevents 
the radiation of the heat liberated at the interior. Under these 
conditions the mixture may become red hot. 

Although, as has been said before, no arrangement can alter 
the amount of heat liberated, the temperature may be regulated 



ACET^T.KNK GEXKKATOES -^-^ 

by haviiio- an excess of water to absorb the heat. Re.c:ardless of 
this there are i^enerators manufactured which do not utihze this 
or any other cooHnq- agency. 

Z)/7> Type Generator.— In this type of generator, small quan- 
tities of water are dropped onto a large mass of carbide. The 
amount of water being regulated by the pressure or quantity of 
the accumulated gas. On account of their simplicity they are 
freciuently used for small portable generators, and when started 
they should be allowed to work continuouslx until the supply 
of carbide is exhausted. These generators give the greatest 
amount of heating and the most impure gas. 

Floodiiii^ 'J'ype c;eiierators.—h\ this generator the carbide 
is placed in i)ans. having dividing walls to separate them into 
compartments containing about two pounds each. The water 
control is arranged to first enter compartment Xo. i, exhausts 
and completely floods it. and then ilows into the next compart- 
ment where it finds a fresh supply of carbide. This overflowing 
from one compartment to the other, continues until the contents 
of the generator are exhausted. These generators possess the 
same disadvantages as the drip type: but not to so marked a 
degree. 

Carbide to ll'ater Type.— These generators are provided with 
a hopper of some sort, which contains the carbide, and are pro- 
vided with a mechanism for automatically dropping it into the 
water below, at the right time and measured quantities to mam- 
tain a constantly uniform pressure. These feeding mechanisms 
are of two kinds, one consists of some kind of a valve or shutter 
which opens at the right moment and drops the carbide directly 
into the water, the other depends on feeding the carbide over 
the edge of the plate. Kither of these arrangements must be 
safeguarded so that it is impossible to accidently drop the entire 
quantitv of carbide into the water. 

The feeding mechanism must be positive, strong and simple, 
for on it depends the perfect, uninterrupted and economical 
operation of the machine. It must ])ositively feed carbide when^ 
it is needed, and with e(|ual reliability prevent the feeding of 



46 



OXV-ACKTVl.KXK UELDiXG AND CUTTTX(. 




FIG. 2 4. 
TYPICAL CARBIDP: TO WATlJK GEXE 



RATOK. 



AC ET ^■ lA'] X H ( ; 1". N !•: i; ATORS 47 

carbide ^vhen it is not needed. The water chamber should hold 
cnouiih water to absorb the heat liberated by the decomposing 
carbide, without excessive temperature, and the carbide should 
be fed in very small quantities (piece by piece) with diminishing 
or increasing- frequency as the demand for gas decreases or 
increases. 

When standing in the shop, acetylene generators are subject 
to accidents and nn'sna])s. just the same as any other piece of 
e(|ni|)ment ; the tang of a hie may be thrown through the shell . 
of the generator and allow the gas to escape. To avoid trouble in 
instances of this nature, the modern generators i)rovide that 
carbide will not feed into the water in C()nse<|uence of lowered 
pressure due to accidents to the generator. This is accomplished 
bv utilizing tlie How of gas. to the service pipe, to operate the 
carbifle \vc(\. 

"Carl)idc to water" generators as just (lescril)ed, generate 
the most i)ure, cool, gas at a constantly uniform pressure. They 
are more economical, safer, and otherwise more satisfactory than 
either the Drip Type or Flooding Type generators. 

There are two different designs in this type of generator. 
One having a gasometer in which a quantity of gas is stored 
ready for instant use ; and the other in which no gasometer is 
required, the gas being generated on demand. (Generators with- 
out gasometers have the advantage of having less gas in storage 
in case of injury from accidental causes ; they are less liable to 
give trouble 1)\- freezing, they are not so cuml)ersome to handle 
and conse(|uently better adai)ted to portable use. 

Sclrcfiiii:; a (Generator. — As to the selection of a generator, 
there are good generators in both of the last named types, and 
it is an easy matter to select the one best suited to your require- 
ments. C)i whatever type it may be, a good generator should 
possess the following qualities: 

(i) It must insure cool generation. Since all machines 
are slightly lieated during rapid generation, a pound of carbide 
decomposed in water always liberates the same amount of heat 
Nine hundred 1'.. T. U's. are liberated from every pound ot 



48 0XY-AC?:TYLKNI'] WKLDIXG AM) crTTING 

decomposed carljide. and tliis heat should lie absorbed in a suf- 
ficient quantit}- of water to insure that no part will become 
heated enough to become dangerous. 

(2) There should always maintain a constant uniform 
pressure, sufficient to insm-e a rapid flow of gas to the torch; 
but never more than 2() pounds. A pressure of 29 pounds at 
any point may become a source of danger and more than 15 
jiounds is uimeccssary. 

(3) It shoidd be well constructed, built of good material 
selected to resist the chemical action of the gases and carbide, of 
sufficient weight and proptirtion to withstand the stress of care- 
less handling. It should be built for service, and not merely to 
sell. 

(4) It must be simjile. A'oid of numerous or complicated 
mechanisms, easy to clean and recharge, and reliably automatic 
in operation. 

(5) It should generate the maximum amount of clean washed 
gas. 

(6) It must be so designed, that if any part fails to work, 
becomes broken or dislodged, it will result in stopping the carbide 
feed. 

(7) The feed regulator should be actuated by the combined 
influences of lowering pressure and flow of gas to the service 
pipe; and should not be actuated bv either one of these in- 
fluences alone. 

(8) It should be e(|ui]ii)ed with ])ressure gauge, safety 
valve, and an interlocking arrangement of the valve handles that 
will preclude the possibility of careless mani])ulation. In other 
words it should be "fool proof." 

Generators of the carbide to water ty])e are undoubtedly 
the best. With the water in excess, it is im]x)ssible for the tem- 
perature to rise to the boiling point of water, and under all con- 
ditions this class of generator yields the purest gas. As the 
acetylene bubbles up through the water it is washed free from 



A (• i: T \' 1 , !•; \ K ( i I-: \ i-: i^ a tors 



49 



most of its impurities. They are perfectly safe to move on 
trucks while charsjed, and under pressure and it is impossible 
for them to explc^le if they are desiQued and constructed on the 
lines prescribed. 




MODKRN AC'Kl-VLI<:.\E (iHNERATOR 



50 



CHAPTER VI. 
OXY-ACETYLENE TORCHES. 




^v/ 'K/ r!** 

<> '. it w 

FIG. 1.".. 

^roDKK^■ oxv-acetylkxk wiildixg torch 

T(i the casual observer, the oxy-acetylene torch is comparative- 
ly a simple construction consisting of a body or handle at one 
end and a mixing head at the other end, e(|uipped with tips or 
nozzles of various sizes to direct the flame against the work; but 
the requirements of this torch are very exacting. 

The velocity of propagation of the oxy-acetylene flame is 
about 330 feet per second, and to prevent the flame flashing 
back into the torch head, it is necessary that the velocity of 
the gases, as they leave the torch, should equal or exceed this 
velocity This "■flashing back" is a condition in which the flame 
enters the end of the torch and follows back into the mixing 
chamber. This feature in a torch is very annoying and causes 
much delay, for it necessitates turning ofT the gases, relighting 
the torch, and adjusting the flame, before proceeding. While 
this is being done the work is cooling, thus the delay and incon- 
venience amounts to more than merely relighting and adjusting 
the torch. 

Acetylene when burned in the air requires about Ave times 
its volume of oxygen to completely consume it. This is also 
true when burning acetylene with the oxy-acetylene torch ; but 
to obtain the best results, it is necessary to only supply one 
volume of oxygen to one volume of acetylene, the other four 
volumes of oxygen being supplied by the air. If more or less 
than one volume of oxygen is delivered by the torch, it results 
in waste of oxygen, or lowering temperature. 



ACETYLENE TORCHES 51 

The intense heat obtainable with this torch is dependent on 
the rapidity of combnstion and this, in tnrn, depends on the 
thorough niinghng- of the gases, so that each atom of oxygen is 
in close association with a molecule of acetylene, ready for 
instant combination. 

To obtain this thorough mixture of equal (|uantities of gas 
and eject them at the required velocity, is more difficult to ac- 
complish than might be supposed. The factors that contribute 
to this (lifficult\- are. the difference in specific gravity of the 
gases, the different pressures at which they are supplied, and the 
varying quantities required by the different tips. 

Another feature to be obtained in a good torch, is that it 
should handle well, or be well balanced to facilitate easy and 
rapid manipulation. When the torch is being used for welding 
it is in constant motion, describing little circles of uniform size 
overlapping each other and equally spaced along the line of the 
weld. The motion is somewhat similar to that of the penman 
writing a series of overlapping loops in a continuous uninterrupted 
line. The reader has perhaps practiced this exercise in penman- 
ship, and knows the importance in having a pen that handles 
right. A well balanced torch is of ef|ual necessity to the welder. 

The foregoing re(|uirements are general and apply to torches 
of either the high or low pressure types. 

According to the pressure of the acetylene supply, oxy-acety- 
lene torches are of two types, the low pressure torch, which is 
designed to use acetylene at a tension of only a few ounces, and 
the high pressure torch designed to receive acetylene at a pres- 
sure ranging from 2 to 12 pounds. 

Low Pressure Torches: — -To obtain the desired velocity at 
the tip of the torch, the oxygen must be delivered at high 
pressure, and to provide equal volumes of gases, at such 
a difference in pressure, it is necessary to utilize the velocity of 
the oxygen to promote the fiow of acetylene. This is accom- 
lished by a device similar to the injector, or aspirator. The oxy- 
gen nozzle opens into the center of a conical chamber, where it 
draw's in the acetylene, mixes, and is then ejected through an ex- 



52 OXY-ACETYLEXE WELDING AND CUTTING 

pansion chamber where the velocity is reduced to a suitable value. 

The oxyg'en being supplied at a pressure so greatly in excess 
to that of the acetylene, it is thought possible for it to blow 
back through the acetylene tubes, and produce in them a com- 
bustible mixture, in fact the first inventors of low pressure 
torches greatly feared the "ilashing back" of the flame into the 
acetylene pipes, and to prevent this they devised many ingenious 
arrangements, which are still indispensable. 

High Pressure Torches : — The design of high pressure torch 
is, in a general wa}-, on the same lines of the low pressure torch. 
That is the injector principle is used ; but not to so great an extent. 

The acetylene and oxygen being used at nearly the same pres- 
sure, there is no tendency for the oxygen to blow back into the 
acetylene tube. A more perfect mixture of gases is obtained, be- 
cause the oxygen does not tend to force a passage way through 
the acetylene ; but remains in association with it long enough to 
become thoroughly mingled. This resuhs in greater economy. 

The high pressure torch is more universal in application, be- 
cause flames of different magnitude arc obtainable by regulating 
the valves which control the gas supply, while with the low 
pressure it is necessary to change the nozzles and mixing cham- 
bers, in consequence of these advantages there is a growing 
favor for high pressure torches. 

To facilitate welding in inaccessible ])laces and permit their 
use in welding machines, high pressure torches are constructed 
in a variety of lengths and shapes, a few of which are illustrated. 
Fig. 15 shows a torch designed for general hand use. It is provid- 
ed with "tips*' or nozzles of different sizes, and by inserting one 
or the other, as the occasion may require, the widest range of 
work may be handled, varying from the thinnest sheet iron to 
the heaviest steel casting. Table XI, in the back of this volume, 
gives the size of tip best suited to the weight of the metal be- 
ing welded, and shows the amount of gases each tip will con- 
sume per hour. 

When large castings have been preheated to considerable 
extent, the heat which they radiate to the atmosphere, makes it 
verv uncomfortable for the welder to stand over them and use 



ACETYLENE TORCHES 53 




/////// 






FIG. Hi. 
OXY-ACETYLENE TORCH. 

This torch is made longer than the standard, to t'ai-ilitate welding in 
places the operator cannot aj)proa(-h on account of inacessihilitv or 
radiating heat. 

the torch. In these instances it is sometimes more convenient 
to use a torch of unusual length, so that the welder may stand 
at a more comfortable distance. These lor.o- torches are fre- 
(}uently used to reach a weld that is impossible for the welder to 
approach on account of it being- inaccessible. These torches 
may be made any length to suit the welder or the occasion : but 
experience has demonstrated that when the length exceeds 36" 
the torch becomes difficult to handle. On this account, torches 
for this purpose are usually made about 34" long. 

All of the standard torches are constructed to direct the tiame 
down at a right angle to the handle, or at an angle varying lightly 
from this position. This arrangement luakes it impossible to do 
welding in the bottom of a tank which is too small for the welder 
to enter, and to facilitate work of this kind, the manufacturers 
have provided, what might be called a Straight Line Torch. In 
this torch the head and mixing chamber are arranged to deliver 
the flame straight away from the operator, or in a line with 
the handle. 

Cutting Torches -.Steel plates 1-8 or 3-16 inches thick may 
be readdy cut by the oxy-acetylene process without any special 
changes in the torches just described; but for greater thick- 
nesses a special torch is required. 




FIG. 17. 
STRAIGHT LINE TORCH. 



54 



OXY-ACETYLENE WELDING AND CUTTING 



A complete description of the oxy-acetylene cutting process 
is described in chapter XII. 

The principle upon which the cutting- torch is constructed is 
to provide a flame to raise the temperature of the metal to red- 
ness and then deliver a jet of pure oxygen against the heated 
surface. Some of the earlier torches resembled the regular 
welding torch with the addition of an auxiliary oxygen tube. 
This tube received its supply of oxygen from a point in the 
handle beyond the control of the needle valves which regulate 
the flame; and delivered its oxygen close beside the base of the 
flame. 




FIG. 18. 
OXY-ACETYLENE CUTTING TORCH. 

It is ])rovided with a valve to regulate the flow of oxygen, 
independent of the supply required by the preheating flame. 

There are several features, of this type of torch, that are well 
to consider. The greatest economy and speed are obtained with 
the purest oxygen. In fact there is considerable eft'ort expended 
in generating and maintaining pure oxygen for this purpose; 
but in torches of this type, if the oxygen is polluted with air just 
at the moment it is to be used, the results are not as satis- 
factory as they might have been, if the jet of oxygen had been 
protected from the atmosphere. 

Since the preheating flame must precede the oxygen jet in 
the line of the cut, it follows that these torches can only be ad- 
vanced in (^ne direction, that is, with the oxygen jet following 



ACETYLENE TORCHES 



55 



the flame. Then, to cut a hole through a plate, the operator 
would have to take different positions around the plate. In 
other words he would either have to walk around his work or 
assume some exceedingly awkward positions to keep the oxygen 
jet continuallv in the rear of the preheating flame. 

Manufacturers of modern torches have overcome these dif- 
ficulties by placing the oxygen jet inside of the heating flame, 
where it is protected from the surrounding air, and is ever in a 
position to do its work, irrespective of the direction the torch 
is being moved. 

When the occasions for using the cutting torch are frequent 
and interrupted, it is desirable to possess a torch designed ex- 
clusively for this purpose; but if the events of its use are only 
incidental, an attachment ma\- be ajjplied to the welding torch, 
which will admirably serve the purpose of the cutting torch, and 
give as perfect satisfaction. 

One or these attachments is illustrated in Fig. 19 which shows 
the \ ulcan Combination Cutting and Welding Torch. This 
combination consists of an auxiliary oxygen tube and cutting 
head, which, when attached to the Vidcan welding torch, makes 
a perfect cutting torch of the nnxlern type ; the ])reheatiug t1ame 
is formed in a hollow annular cone, with the oxygen cutting jet 
in its center, as described in a previous paragraph. 




X/' 



FIG. 19. 
VULCAN COMBINATION CFTTIXC, AND WELDING TORCH. 



56 OXYACETYLEXK WKLDIXG AND CTTTING 

Instructions on Assonblin;^. Wilcaii combination and weld- 
ing- torches are furnished assembled and ready to use, but when 
a customer has previously ])urchased a welding t()rch, and at 
a later period orders a cutting- attachment, he may require some 
instructions on how to asseml)le the coml)ination. 

.Assembling these parts is only the work of a very few moments, 
and if the same routine is followed each time, the performance 
becomes habitual, and the combination is made very C[uickly, 
without distracting the operator's attention from other w^ork. 
An outline of procedure is recommended as follows, the parts 
and letters referred to are indicated in big. 19. 

To (|uicklv assemble this combination, imscrew the miion 
nut (." and remove the cutting head from the tube. 

Then attach cutting head to the head of the torch by screw- 
ing A into R up to the shoulder on A. and tighten by hand. Tf 
the cutting head does not align with the torch it should be 
made to do so, by loosening the nut D and swinging it to the 
position shown in the illustration. When this position h.as been 
obtained the mit D must l)e screwed down tight onto the cutting 
head. 

The small machine screw 11 should then be removed from 
the clamp G and the clamp slipped over the handle on the torch 
at I. 

Attach E to F and attach the tube to the cutting head by re- 
turning the union nut C to its original position .shown in the il- 
lustration. Then replace and tighten the machine screw H. 

See that the thumb lever O is up in the released position, 
which closes the oxygen valve J, and close the needle valves L 
and M. 

The torch is now ready to be connected with the hose. At- 
tach the red acetylene hose to the lower connection and the 
black oxygen hose to the recently applied upper connection. 

The oxygen and acetylene gases are ignited at R and the 
tips N are not used in cutting. 



ACETYLENE TORCHES 



57 



To remove the cutting attachment, disconnect the oxygen 
hose, remove machine screw H. disconnect E and, C and remove 
the oxygen tube by slipping clamp G from the handle of the 
torch ; then unscrew A from B, attach the black oxygen hose to 
the upper connection K, select a tip from N and insert it into B. 
The torch is then ready to use for welding. 

Figure iS shows the complete combination torch. 




FIG. 20. 
TOF{('H DKyiGNED FOK WKLDING MACIUNKS. 



58 

CHAPTER 7. 

PRESSURE REGULATORS. 

When oxygen or acetylene is obtained in drums at pressures 
ranging between 150 and 1,800 per square inch and used at the 
torch at pressures ranging from i to 54 pounds, it 1)ecomes neces- 
sary to employ some automatic mechanism that will make this 
reduction, and maintain a constant uniform pressure at the 
torch, irrespective of the original and constantly diminishing 
pressure in the drums. 

The device used to perform this work^ is known among weld- 
ers as an automatic regulator and accomplishes this regulated 
pressure reduction by automatically throttling the gas supply so 
that the pressure will remain uniform at the torch. As the gas 
enters the regulator it passes through a valve into an expansion 
chamber, one side of which is a flexible diaphragm. If the quant- 
ity of gas entering \h\> expansion chanilKT exceeds the quantity 
going out to the torch, there will be a natural tendency to in- 
crease the pressure, but this increasing pressure, deflects the dia- 
phragm and partially closes the valve ; thus the gas is admitted or 
throttled to suit the increasing or diiuiiiishing demand at the 
torch. 




Fig. 21 
AITOMATUJ ACETYLENE REGULATOR 



PRESSURE REGUEATOKS 



5c^ 



These regulators are provided with a spring and adjusting 
screw arranged to hear (hrectly on the (Ha])hragin. so that the 
final pressure may he adjusted to suit the requirements of the 
work. 




AUTOMATIC ().\V(n-:\ REGULATOR 

They are usually provided with one or two gauges to indicate 
the pressures in the drum and at the torch. 

A low pressure regulator equipped with one indicator is shown 
in Figure 21. The indicator dial shows the pressure of gas going 
to the torch, and the T handle on the front is used to adjust this 
pressure as the requirements demand. 

This type regulator is usually used on acetylene generators, 
hecause in this service it is only required to know the pressure of 
the gas going to the torch, the pressure in the generator hemg 
indicated hy an independent gauge. 



60 



OX Y- ACETYLENE WHLDING AND CUTTING 



A high pressure regulator with two indicators is shown in 
Figure 22. One indicator shows the pressure in the drum, and 
the other the pressure of the gas going to the torch. When used 
on oxygen drums the high pressure incHcator is useful in deter- 
mining the amount of gas in the drum as explained on page 26. 
it is therefore, sometimes called an Oxygen Regulator. 




OXY ACETYLENE WELDLXG I'LANT 
Showing application of automatic j)ressure regulators 



ACETVLKN K GKXKK ATOR 

CHAPTER 8. 



61 




Fiji. :!<• 
vri/'AX A^To^rATI(' acktvt.ene gknkhatok 

Chapter five outlines the various types of generators that can 
be used to prockice acetylene gas. In reading over the advantages 
and disadvantages of the different methods of generating ace- 
tylene, it will be noted that the "carbide to water feed" genera- 
tor has none of the disadvantages of the other types, but does 
have a great many advantages that arc not possessed by the others. 

Of the two styles of generators, low and medium pressure, 
the latter is the better for welding, because the acetylene and 
oxygen, should be delivered to the mixing chamber of the weld- 
ing torch at as near the same pressure as can be secured. 



62 OXY-ACETYLENE WELDING AND CUTTING 

Where both gases are thus combined under positive, even 
pressure their mixture is more complete — assuming that the mix- 
ing chamber of the torch is properly constructed. Unless this 
thorough mixing of the two gases takes place, the result will be 
incomplete combustion, hence waste of gas and loss in efficiency. 

With the low pressure or gasometer type of generators, the 
injector type of torch is principally used. By this is meant that 
oxygen under high pressure, in passing through the mixing cham- 
ber of the torch, sucks the acetylene through with it. In this 
way the two gases are not thoroughly mixed, and the result is a 
waste of gas and a poor weld. I'he feeding mechanism of 
most pressure generators, now on the market, are ()])erated by 
means of complicated clock-work with pulleys and weights, leath- 
er diaphragms, etc. These frequently get out of order at just 
the time when operator needs the gas the most and the resulting 
delays are expensive as well as annoying. 

The Vulcan automatic acetylene generator works on entirely 
new principles, and the features that contribute to its success are 
so simple, unique, and |)erform their duly so accurately that the 
generator is well worth consideration. 

Its design is such that the demand for gas or the flow of gas 
to the service pipe, working in conjunction with the amount of 
pressure in the generator, automatically regulates the gas genera- 
tion to meet the varying demand at a uniform pressure. The 
rate at which the carbide is fed into the water varies directly 
with the rate at which the gas is used, and no more carbide is 
fed than is absolutely necessary to maintain the pressure at that 
particular moment. If gas is being used and pressure up to 
normal, or vice-versa if the gas is not being used but the pres- 
sure below normal, the carbide feed is inactive; but under these 
conditions a very slight dro]) in pressure, or the renewed de- 
mand for gas will cause the right amount of generation to take 
care of the moment's demand. 

The carbide feed automatically drops small quantities oi i% 
yi}i carbide, deep into a liberal quantity of water, and as the gas 
bubbles rise to the surface, they are cooled and washed, and 
emerge free from dust or other impurities 

P)y the arrangements set forth, many advantages are obtained. 



AC ET YI. KN E G EX E K ATO K 



():> 



The most apparent of which is a very constant uniform pres- 
sure. After generation is eliminated on account of there being 
only a ver)- small quantity of carbide dropped at one time, and 
the gases are cool because there is not sufficient reaction taking 
place to perceptibly raise the temperature of the large volume 
of water. The i>4x^ carbide used in this machine generates 
one half a cubic foot more gas per pound, than the quarter or 
finely crushed carbide, and since all sizes (»f carbide are re- 
tailed at the same i)rice this feature alone effects a saving of 
I2>4 per cent in the cost of generation. The motor that operates 
the carbide feed is imposed between the generating chamber 
and the service pipe, and for the reason that it is not operated 
by the deminishing gas pressure only, but by the flow of gas to 
the service pipe combined with reducing pressure, the arrange- 
ment is an assurance that all the carbide will not be fed, or an 
excessive amount of gas generated, should the gas holder be 
accidentally punctured. The last mentioned, is a common fault 
of generators actuated by reduced gas pressure only. 



^..^M 





Fig. ;!i 

VULCAN GENERATOR WELDING PLANT 



64 OXY-ACETYLEXE WELDING AND CUTTING 

A word about the unique features of the motor will interest the 
reader. The runner or wheel from which power is received is 
entirely incased and not visible, but when removed it resembles 
an old-fashioned over-shot water-wheel. With the water-wheel 
power is derived from the weight of the water, in the buckets, 
descending" and rotating the wheel : but the wheel of the Vulcan 
motor is submerged in water and operated b}' the buoyancy of the 
gas gathering under the inverted concave buckets and rotating the 
wheel, in its ascent from the generating chamber to the service 
pipe. The arrangement is such that if the pressure is up to nor- 
mal, the gas is diverted through a by-pass, to the service pipe, 
without rotating the motor. 

In this description the reader will note the absence of springs, 
clock-work or weights which might make the apparatus cum- 
bersome. 

The generator is designed to deliver gas, at twelve pounds 
pressure, to oxy-acetylene welding and cutting torches. The pres- 
sure selected is deemed most suitable for the work. 

The suggestions and rules of the consulting engineers of the 
National Board of Fire Underwriters are strictly followed, in the 
manufacture and construction of Vulcan Acetylene Generators, 
and every precaution has been taken to insure safety and effi- 
ciency. The materials are the best, the proportions ani])lc, and the 
workmanship accurate, so that with proper handling the opera- 
tion will be eminently successful. To insure that these generators 
will be properly handled by even the most careless operators, 
each generator is equipped with a system of guards so inter- 
locked that it is impossible for an absent-minded operator to make 
mistakes. In fact there is only one way they can be manipulated, 
and that is the right way. Although it is impossible to pursue 
wrong methods in operating this plant we will outline the prop- 
er method. In this outline the parts referred to are indicated in 
Figure 32. 

Pipe Xo. I is the blow-off and should be extended, witliout 
traps and as few elbows as possible, to the outside of the building, 
and the end pointed down to exclude snow, birds, etc. Pipe Xo. 
2 is the service pipe and, if the shop is piped, it should be con- 
nected to the supply line, but if it is intended to use gas directly 



ACHTVLi:\K GKXKRATOK 65 

from the generator, thougli the hose, connect pipe Xo. 2 with. 
the acetylene regulator. 

Fill the chamber Xo. 3 and motor case Xo. 4 wiili water 
through liole Xo. 5 and allow to stand a few minutes for air hul)- 
hles to work out. 



•S^rfrv i/e^ r **^ 




ixti:kmok ok ntlcax oKXiiirvroij 

]'>efore replacing the plug into Xo. 5 be sure the motor case is 
filled to oversowing. 

lo charge, or recharge the generator relieve the pressure by 
turning lever Xo. 6 one-(iuarter turn to the right, then agitate 
the sediment so ii will run (Uit. b\- n^atin^ the crank Xo. 7. Open 
the locking device by turning handle X'o. 8 one-quarter turn to 



66 OXY-ACETYLKXK WIOLDING AND CUTTING 

the left. Draw ofif the sediment throug"h sludge cock by ttirning 
handle Xo. 9 one-quarter turn to the left. After draining, close 
sludge cock before proceeding further. 

Now swing lever No. 10 to a horizontal position and fill the 
lower part of the generator with water through funnel No. 1 1 
until it overflows through No. 12; then return handle to Xo, 10 
to its original vertical position. Remove cover No. 13, fill the 
carbide hopper with 1 '4x^carbide, rei)lace cover and tighten 
cap screws even and equally. Lock up the generator by swinging 
lever No. 8 to the right in its original position and closing lever 
No. 6 to the left over it. Put valve handle No. 14 in 1 vertical 
])osition which closes the service cock. 

The generator is now ready for pressure which is started by 
rotating gear wheel X'o. 15 to the left until the pressure gauge 
indicates about three pounds. The carbide will then feed auto- 
matically and the pressure rise to the proper amount as soon 
as the service cock is opened and a little gas drawn oflF rh rough 
the torch. 

From this on the A'ulcan Generator is entirely automatic and 
needs no further attention until the contents are entirely ex- 
hausted. 

On account of these generators being self contained, com- 
pact in form, and complete without the necessity of a cumber- 
some gasometer, they are very suitable for portable purposes. 

One of these generators mounted on a truck, with oxygen 
drums and tool box. is shown in Figure 33. This makes a com- 
plete portable plant which may be taken to the work anywhere 
alxnit the shop or yards. 

/ 'nlcau Generators are Safe because there is less surface sub- 
jected to injury than in many other types. 

There are no pipe connections between widely separated parts. 
They are less liable to freeze than generators having gasometers. 
Every movable part is safe guarded in a way that makes them 

fool proof. 
The carbide charge camiot be accidentally discharged into the 

water. 
It cannot be overfilled with water. 



ACETYLENE GENERATOR 



67 




Fiji. ;;;: 

VULCAN PORTAHLK (iKNKRATOR PLANT 



(58 OXY-ACETYLEXE WELDIXG AXD Ol'TTlXG 

CHAPTER 9. 

OPERATING PLANTS. 

This might be more correctly called operating;" a welding" shop, 
for it is the writer's intention to call attention to a few of the 
essential details, both in equipping and operating a shop. The 
subject covers such a range of information, that it would be im- 
possible to mention every detail, in fact it would not be practical 
to undertake such a task, for the equipment will be great or 
small, according to the amount and nature of the work which the 
operator expects to provide for. 

Whether the amount of work is considerable or not, there is 
one thing that should be uppermost in the mind of the operator, 
that is thoroughness and excellency of work. No matter how 
small or how large the job. the welding sliould l)c thoroughly, 
carefully and conscientiously performed. After a job has been 
finished it is often difficult to determine whether it is well done 
or not, this information may only be obtained by observing the 
welder while he is doing his work or testing the weld after it has 
been finished. Sometimes it is impractical to do either of these, 
and the integrity of the welder must be relied upon. 

Recognizing this truth, it is often the practice of boiler in- 
spectors, to condemn any welding on boilers which has not been 
done by welders of "known reputation," and since boiler work 
covers a large per cent of the field of his usefulness, the welder 
should make every effort to get into the class of welders of 
"known reputation." This also applies to other kinds of work. 
The occasions that require autogenous welding are frequentl}' 
of great importance. It may be a crank shaft or cylinder for 
some power plant, and if the welder does his work thoroughly, 
the job will hold and be as good as a new j^iece : l)ut it he is hasty 
or careless it will be very liable to fail, resulting in loss of time, 
money and possibly loss of life. For this reason persons who 
have work of this kind are wont to ])atronize welders of "known 
reputation." 

In work of the kind just described, the saving in time and 
money is sufficient to pay the welder handsomely for all the 



OI'KHATIXG PLANTS 69 

time, care, or expense he may devote to thoroughly doing- his 
work and there is no excuse for slighting the job on the pretext 
that his customer will object to the expense. The only com- 
plaint that could justly be made, would be for time covered by 
idleness, for lack of foresight that may cause loss of time or de- 
lay, or charging for a service which you are not ecfuipped to 
render. 

Any equipment the welder can provide, will lessen the cost 
of the work and often facilitate better work. Therefore equip- 
ment sufficient for the work you expect to handle is an asset, 
which can hardly be dispensed with. Such conveniences as an 
assortment of handy tools arranged within easy reach, benches, 
brick welding tables, preheating furnaces, and facilities for hand- 
ling heavy work, contribute to good service and the pleasure 
of work, and are conveniences that may be built and installed 
during ones spare moments. 

Many welders have started their plant in a very modest way, 
buying their gases in drums and in every way curtailing the 
amount of the original investment. As their btisiness grew their 
mind was occupied in pursuing their trade, and the fact that 
their acetylene was costing them more than twice as much as it 
should, (lid not occur to them until they learned that a competi- 
tor charged one cent a foot for acetylene and made profit on 
it; whereas he could not make a profit on acetylene at 2 T-4C n 
foot. This leads to the explanation that acetylene in drums has 
an economic place in plants that have to be quickly transported 
to some remote location, over rough roads, in cold weather and 
also in shops where the occasions for using the apparatus are not 
very frequent. The cost of acteylenc in drums is 2c per foot 
at the recharging station and to this cost is added freight and 
cartage, while the cost of acetylene generated on the premises 
of the welding shop, seldom exceeds 7-8c per foot. In a shop 
where the welder uses the torch 6 hours a day, the saving ef- 
fected, by generating his own acetylene, will amount to $2.50 
or $3.00 per day. 

In shops that are provided with an acetylene generator it 
is advisable to give it a permanent location in some corner 
where it will be out of the way and protected against freezing. 



70 



OX Y- ACETYLENE WELDING AND CUTTING 



The advantages of a permanent location for the generator are 
many. The time used in trucking it around the shops is eHm- 
inated, the blow off and shidge pipes can be extended to out- 
side the building, water may be piped to a place convenient to the 
generator, the generator will be less liable to become injured 
by collision, and the acetylene may be piped to any part of the 
building with drops and hose connections at different places most 
convenient to the work. 

Piping: — Acetylene generators are usually regulated to con- 
trol the gas pressure at about 12^2 pounds per square inch and 
since the largest tips consume gas at very nearly this pressure, 
it is essential that the gas should be conveyed through the 
pipes with as little loss of pressure as possible. It is recom- 
mended that the loss of pressure should not exceed 8 ounces. 
The factors to be considered in determining the loss in pres- 
sure are, the length and diameter of the pipe, the specific grav- 
ity and the initial and final pressures of the gas. The quantity 
of acetylene which will be delivered through pipes of different 
sizes with a loss in pressure of 8 ounces from an initial pres- 
sure of 11V2 pounds, may be calculated from the following 
formula, in which (D) represents the inside diameter of the 
pipe in inches and (L) its length in feet. 



2809 \ 



26 D' 



quanty of gas. 



TABLE IX. 

ACETYLENE DELIVERED BY PIPES OF VARIOUS 
SIZES AND LENGTHS, WITH LOSS OF 8oz. PRESSURE 
FROM AN INITIAL PRESSURE OF 113^ LBS. 



Xoniinal 

Size of 

Pipe 






Leugth of Pipe in feet 




100 1 


200 

306 

616 

1,144 

2,266 


300 
^250^" 
503 
934 
1,850 


400 

~216 

436 

809 

1,602 


500- 


600 


700 


1^ 


434 

872 

1,618 

3,204 


193 

390 

723 

1,433 


177 
356 
660 

1,308 


163 

329 

611 

1,211 


% 


1 


114 









OI'KKATIXU PLANTS 71 

In using this table the pipe fitter should add to the actual 
length of the pipe, a sufficient length to compensate for the 
fittings, as obtained from table VIII. 

The effect of a bend or sharp angle in a pipe is to retard the 
flow of gas. This is least when the radius of the bend is five 
times the radius of the pipe. The most convenient way of stat- 
ing the resistance offered by bends, is in terms of equivalent 
length of straight pipe which offers the same resistance to the 
flow as the extra resistance due to the bend. A formula given 
for this equivalent length is 



L = 12.85 



1 



L=equivalent in feet 

r=radius of pipe 

R=radius of curve 

]=:rlength of curve in feet measured on center line. 

The following table gives the additional length required to 
equal the friction due to globe valves. For standard elbows 
and trees, take ~/s the value given in the table. 

TABLE VIII. 

ADDITIONAL LENGTHS OF PIPE THAT WILL 
CAUSE FRICTION EQUAL TO THE FRICTION DUE TO 
GLOBE VALVES. 

Diameter of pipe Additional length 

in inches. in feet. 

1 2 

i>4 4 

2 7 

2>4 lO 

3 13 

4 20 

5 28 

6 36 



72 OX Y- ACETYLENE WELDING AND (TTTING 

The blow-off or exhaust pipe should extend to the outside 
of the building with as few elbows as possible and terminate with 
the end pointing- down to exclude the snow and water. 

The sludge pipe or drain pipe as it is commonly called should 
not lead direct to a sewer, but should first discharge into an open 
pit. This pit may be provided with an overflow, about 3 feet 
above the bottom, which may then lead to a sewer. The pipes 
from the generator to the pit should have a fall of about one 
inch to twelve feet and from the pit to the sewer one inch to 
20 feet. If a sludge pit is constructed that will drain and leave 
the residuum comparatively dry. this material may become of 
some pecuniary value. The chief uses of the sludge, frequentlv 
called acetylene lime, are for mixing mortar, for whitewashing 
fences, cattle pens, fruit trees, etc., for making paths, and for 
fertilizing, with some occasional application as an insecticide and 
disinfectant, mortar made from it is reported to bind quickly and 
hard ; there is no reason why mortar made from it should not 
be at least of equal value with mortar made from slaked lime. 
It may be added that any of the uses to which ordinary lime 
white wash is applied, a white wash made of carbide residuum 
answers equally as well. 

In view of the mauy particular uses U) which acetylene lime 
has been successfully applied, and particularly because of its 
usefulness as a fertilizer, it may not be out of place to submit 
the chemical analysis of carbide residuum. The following figures 
show the analysis of three specimens of residue taken at remote 
places. 



Sand (silica) 

Carbon (coke or coal) 

Oxide of iron and aluminum 

Lime 

Water and carbonic acid 

The services pipes, or mains that connect the generator with 
the torches must be securely fastened, without sags that may 
form pockets and when practical, they should drain toward the 



1 




-^ 


3 


r cent 


P< 


?r cent 


I'er cent 


1.24 




1. 10 


•97 


2.08 




3-95 


2.14 


311 




2.9 


2-3 


62.5 




63.65 


66.1 


31.04 




28.4 


28.47 



OPHKATIXG PLANTS 73 

g'enerator. It is advisable to use g;alvanized pipe because the 
acetylene is usually a little moist and forms oxide of iron, which 
comes off in a powder and may accumulate in certain parts. 
Pipes of red copper are strictly prohibited because the acetylene 
and copper can form acetylide of copper, which is spontaneously 
combustible. 

Tcsfiiii:; : As soon as the pipes are all in place and are prop- 
erly secured, the system should be tested, to find whether it is 
perfectly s^as tight. A convenient nipple should be selected for 
making- connection to the proving- pump (an ordinary auto pump 
will do), and every other opening or fitting should be tightly 
closed. The pump may then be connected and air forced into 
the system imtil the pressure .gauge registers 14 or 15 pounds. 
The pump should then be shut off. leaving the gauge under press- 
ure. Tile extent of the leak may be judged by the rapidity of the 
fall in pressure ; but its location must be found by following the 
pipe line and listening for the hiss of escaping air and by apply- 
ing soapy water to the joints, with a heavy brush. 

The oxycetylene welding and cutting outfit is the best tool 
for making the pipe connections, for with it the pipes may be 
cut to any length, heated for bending, and the joints welded. The 
welded joints will never leak or give trouble whereas screwed 
joints might leak. 

After the pijjcs have been thus ins])ected and proven satisfac- 
tory, the i)ressure mav be released, the generator starte<l. and 
the gas ])ressure raised to 12 or 13 poimds. After a little gas has 
been drawn oft" at the extreme ends of the pipe and its branches, 
it should be tightly closed and allowed to stand at the pressure 
stated, for several hours. Then if there are any leaks, their 
presence will be noted by the smell. A mixture of acetylene and 
air in the proportion of i to i(X)0() can be clearly detected bv the 
smell. Do not hunt for leaks with a light. 

Leaks in The Oxygen Pipes: — Oxygen is an odorless gas 
and its abundance in the room is ueither noticeable nor harmful, 
but it is certainly not a very economical practice to allow it to 
escape, although it is nt>t harmful nor e.x])losive itmay be a source 
of danger, if allowed to blow against the clothing while the 
torch is being used. 



74 OXY-ACETYLENE WELDING AND CUTTING 

If oxyi^en is blowino- against the clothes they are extremely 
inflammable and will ignite Avith a small spark from the torch, the 
flames may extinguish themselves by evading the oxygen, but a 
bad burn may result before this is done. 

Read Instructions: — Carefully read all the instructious attend- 
ing the apparatus, go over each piece and understand it before 
attempting to use it. This may save long delays and much 
correspondence, for it is not an uncommon thing for manufac- 
tures of welding apparatus, to receive complaints that the torch 
would not work, the tips would not flt. or that parts were miss- 
ing and after long correspondence, learn that the apparatus was 
all right ; but the customer had neglected to read the instruc- 
tions and (lid not know how to assemble his equipment. 

Weldijig Tabic: — Aside from the work benches and tools, one 
of the first requisites of the welding shop is the welding table. 
Whenever the work to be welded is not too large or too difficult 
to manipulate, the operation is best carried out on a table. 
These tables should be entirely of metal except the top which 
may be made of a good grade of brick, preferably fire brick. 
The nature of the work to be handled on them, will, of course 
regulate their size ; but a table 4 feet by 6 feet and 24 inches 
high will be best suited to the average run of work. For light 
welding on aluminum work they may be made a little higher, 
T,T, inches being a good height. These tables are best built of 
2^/2x2^x3-16 angles assembled and welded with the torch. The 
welded joints give the lal)lc rigidity and make the beginner 
familiar with the work. The material required for the table 
described above would consist of 4 pieces of angle 6 feet long. 4 
pieces 4 feet long, 4 pieces 2 feet long, and 7 pieces of lightei 
material 43 inches long. The 6 and 4 feet lengths are welded 
together at the corners with one leg of the angle standing verti- 
cal and the other projecting inward, making two frames 6 feet 
bv 4 feet out side. One of these frames is used for the table 
top and the other for a tool tray beneath. The 2 foot lengths 
are used for legs, fitting the inside of the angle over the corners 
of the frames and welding them. The bottom of the tool tray 
should be about 10 in. above the floor and fitted with about 16 
gauge steel sheet. The 43 inch lengths will be spaced 9 inches 



OPERATING PLANTS 75 

apart and welded between the edges of the angles forming the 
table top. The top of the horizontal leg of these angles will be 
flush with the horizontal leg of the angles forming the table top, 
and the vertical leg will extend below^ Their purpose is to sup- 
port the brick filling, composing the top, and for that reason 
thev should be placed beneath the joints of the brick. Figure 2^^ 
shows one of these tables with part of the brick removed to ex- 
pose their support. 




Fijr. •2:', 
WELDING TABLE CONSTKUCTED OF ANGLE IKON 



On these tables, there can be built, tem]iorar\- ])reheating 
furnaces for heating work preparatory to welding, or they 
may be designed to include permanent furnaces formed in the 
brick work of their top. Here is an opportunity for the welder 
to display his ingenuity in designing a combined table and pre- 
heating furnace. 

Some manufactures build a combination table, or more cor- 
rectly, a combination tool consisting of an iron table top witli 
slotted holes for clamping down work, a long \ bar, blocks 
for aligning and welding crank shafts, and a swivel vise lor 
holding irregular shaped pieces. The top portion of the stand 
incorporates a ball and socket joint, which permits rotating the 
work or clamping it at any angle that will facilitate easy manii)u- 
lation. The tool is a great convenience and may be classified 



76 



OXV-ACETYLENE WELDING AND CUTTING 



among the time saving' devices that go to make np an up-to- 
date shop. 




Fi.u. 
COMBI NATION W 



DINC TAHIJ-: 



Preheating Furnaces: — For reasons, which will be described 
fully under the chapter on welding, any welding shop is in- 
complete without some provision for preheatino- and slowly 
cooling his work. In the absence of a special furnace one should 
always have the material at hand for building a temporary af- 
fair of brick and sheet asbestos. These are very quickly and 
easily constructed and serve their purpose very well. Even when 
shops are equipped with permanent preheating furnaces, there 
will be occasions when special furnaces will be required for 
s]>ecial work, and in view of this fact it is well to describe the 
method of their constructitJU, so the beginning will be prei)are(l 
when the occasion comes. 

Ihiilding a h'liniace: — The article to be heated is placed on 
one of the brick topped tables, previously described, and blocked 
up with brick. Around this is layed a course of brick about 
six or eight inches awa}" fmm the article, and ])laced end to end 
with a space of about an inch and a half between them. These 
spaces are for air draft and on rare occasions it may be neces- 



OPKRATIXG PLANTS 77 

sary to remove a brick from the talkie top, to admit air to the 
interior. On top of this course are piled other brick, built nke 
a wall to a height a little above the top of the piece to be welded. 

The fuel used is charcoal, which is made into an even bed all 
around and beneath the article. Sheets of ^i^ inch asbestos are 
layed loosely over the whole furnace and the charcoal ig-nitei 
through the holes at the bottom of the wall. The article should 
be arranged so that the part to be welded will be ui)i)ermost. 
Then when the pro])cr temperature has been attained, an open- 
ing can be made through the asbestos and the weld finished 
without removing it from the fire. 

\'ery often gas burners may be procured, from the dealer, 
which may be connected with the acetylene pipe and found very 
convenient for preheating. It may be added that burners de- 
signed for city gas might not give satisfaction when used with 
acetylene. If one intends to equip with preheating burners, it is 
best to procure burners designed for the gas he intends to use. 

Protecting Apparatus: — Oxy-actylene cutting and welding 
apparatus are not classified among the delicate instruments that 
are liable to become dearranged and out of order: l)ut thev de- 
serve and require care. 

They are designed to maintain the purit\- of the gases. To 
generate cool and commercially pure acetylene at a continually 
uniform pressure and deliver it to the torch in the same con- 
dition. The oxygen is reduced from an extremely high pressure 
to a very low one and this reduction is regulated to a nicet\ . The 
torch mixes these gases in exact proportions and burns them in a 
small but exceedingly hot flame where the gases are completely 
burned and none escape unconsumed. The manufacturers of 
carbide, from which the acetylene is made, exercise the greatest 
care to secure and use none but the most pure material; and 
the manufacturers of oxygen struggle to maintain a standard 
whicli does not vary three tenths of one percent, from perfectly 
pure gas. 

The manufacturers go to all this trouble because tliev un- 
derstand and know that such precautions are necessary to pro- 
duce the best results in the welding shop, and tliese details have 



78 OXY-ACETYLEXE WELDIXG AXD CTTTIXC) 

been mentioned here to admonish the welder to keep his apparatus 
clean and protect it from harm, for it is not reasonable to pre- 
sume that good work may be done when the appliances are kept 
in a careless or slovenly manner. 

All acetvlene p^enerators use water in their operation and for 
that reason they must be protected from freezing. The quantity 
of water is proportioned to the amount of carbide they hold and 
if the sediment of carbide is allowed to accumuhite in the bot- 
tom of the generator it reduces the water capacity and causes 
other irregularities in its operation. It is therefore a gool rule 
to never fill the generator with fresh carbide until after the 
sludge has been cleaned from the bottom. 

Oxvgen is stored in the drums under very high pressure, and 
if this pressure is suddenly admitted into the regulator, it is liable 
to injure the mechanism of the regulator, or pressure gauges. The 
valve on t()[) of the oxygen drum should therefore be opened 
slowh- and left wide o{)en while in use. 




OPEX THE VAI,\K ON TlIK ()XV(;i:X DIU'M SI.OWI.V 



Before opening this valve it is well to liave the adjusting 
screw on the regulator, unscrewed until it is quite free and 
other valves closed. 



OPERATING PLANTS 



79 



Hiere should be some arrangement to securely hold the oxy- 
gen drums in an upright position, for on account of their narrow- 
base thev ma\- be easily knocked over and in this event the valve 
is liable t') be iniured. 



B-a 




K'K.\I()\AHI>K MASK FOIJ O.WCiKN DRl'MS 



Some manutacturers provided a removable base which may 
be api)lie(l to oxygen drums to prevent their upsetting. This a])- 
pliance allows more freedom since the drum is not confined to 
any particular location for securing, but may be moved about 
at the welder's convenience. 

When welding over a ])reheating fire, where the article 
being welded is imbeded in glowing coals, it is good practice 
to shield the torch from the direct heat of the fire, w^ith sheets of 
asbestos. 'The first time the torcli is used over the direct flare 



so OXY-ACETVl.KXK WKLDTXG AND CUTTINa 

of the fire there will probahly be no perceptible harm done to it: 
but a repetition of this practice will, in time, damage it. 

Flashing Back: — While the torch is overheated in this way it 
may cause temporary annoyance by flashing; back. This annoy- 
ance may be removed by cooling the torch in water. If in the 
course of the work it is desired to cool the torch in this way, 
the acetylene should be completely shut oft' and the flow of oxygen 
reduced to a very small amount. The object in leaving a small 
flow of oxygen is to prevent water entering the torch, by the 
eflux of gas from the tip. 

The propagation of the oxy-acetylene llanie is about 330 feet 
a second. This is the speed at which a flame will travel through 
a tube containing a proper mi.xture of oxygen and acetylene. If 
the g"ases are not expelled from the tip of the torch at a speed 
equal to or greater than this, the flame will follow back through 
the tip into the chamber where the gases are mixed and the torch 
is said to "Flash T.ack." While the gases arc l)urning in the 
torch, it is not an imusual occurrence to see long, slender, yellow 
streaks of flame shoot from the tip. 

If the torch is permitted to do this fre(|uently, or t(^ continue 
burning in the head for a short time, it damages it and makes 
a repetition of this "Flashing Rack" more probable. The gases 
should therefore be turned off immediately, shutting off the 
oxygen first. 

The "Flashing Back" is more usually caused by an insuft'icient 
gas pressure, and if both gases are turned on a little stronger, and 
the tlame readjusted to "neutral" the trouble will usually cease: 
l)ut insufficient pressure is not the only cause which may effect 
"Flashing Back." If the torch is held close enough to the work 
to impede the flow of gas, it may "Flash Back ;" but in this event, 
other conditions being" normal, it should relight when it is with- 
drawn. If the tip is mutilated or roughened inside or at the 
end it ma\" produce eddy-currents that will cause "Flashing 
Back;" or if the torch is held too close to melted metal, the force 
of the gas may splash the metal into the tip and ])roduce eddx- 
currents that will cause the same eft'ect. 

Clean Hose: — Oxygen will not burn. \n the presence of sub- 



OPERATING PLANTS 81 

Stances containinj;- carljon or hydrot^x-n it max produce flanie ; 
but it is tlie carbon or hydrogen wliich Inirns. and the oxygen 
supports conil)ustion. 

If the oxygen hose are allowed to lay around on a floor 
that is soaked with kerosene or lubricating oil. the oil will creep 
into the end and when the oxygen is turned on. the hose will he 
liable to burn. This can cause no further damage than to destroy 
the hose, for if the oxygen and oxygen drums are pure and clean. 
the tire can not enter the drum. 

Acetylene is a carbonous gas and may leave slight deposits 
of carbon on the inside of the acetylene regulator and hose, if 
the acetylene regulator and hose are used in the oxvgen service 
they are liable to be damaged by the combustion of these carbon 
deposits. 

.Icctylriic III Dniiiis: It has been explained under the chap- 
ter on chemistry that acetylene under high pressure might be- 
come dangerous to handle : but dissolved acetvlene in drums. 
under ])ressure. has extended the u.sefulness of the gas to a won- 
derful extent. Acetone is a hydro-carbon and the product of dis- 
tillation of wood. It is a colorless, inflammable tlnid and is much 
used in the manutacture of chloroform, iodoform, and other medi- 
cal preparations. This long known Init rather tni familiar lluid 
is an excellent solvent for acetylene, which dissolves in it as freely 
as sugar does in water. The solubility increases with pressure 
and at atmospheric temperatin-e and pressure it will (lis.solve 24 
times its bulk of acetvlene. 

This j)henomenon is utilized to the great advantage of the 
welder by dis.solving acetylene in drums of acetone. The drums 
suijplied are 33 inches long by 8 inches in diameter and contain 
100 feet of acetylene. They are perfectly safe to handle, conven- 
ient for portable purposes, give no trouble b>' freezing, and the 
gas is cool, clean and dry. Since the gas issues at a high pres- 
sure. It is necessary to employ a regtilator to bring it down to the 
pro])er working pressure. 

Portable Acetylene Dniin Plant: — A small but very conven- 
ient plant, in which dis.solved acetylene is tised. is shown in 
figure Xo. 27. This |)lant consists of two dnuns of oxvyen and 



82 



OXV-ACETYLENI-: WELDIXG AND CUTTIXG 



two of acetylene with the necessary complement of torches, 
reg^ulators and apparatus to make up a complete outfit. One 
drum of each oas is mounted on a truck for convenience in mov- 
in.q- and the other two drums are used for storage. 

The plant is always ready for use and while the acetylene costs 
a little more than in the generator plants, it is perfectly practical 
tor the man who does only a moderate amount of work. 

A paragraph on cotmecting and operating a plant of this de- 
scription will not he out of place. The numhers and parts re- 
lerred to will he found in figure Xo. 27. 




t'OHTABlJ-; IVLAXT ISIXG DISSOLVED ACETYLENE 



OPERATING PLANTS 83 

Connect the oxyi^en reijulator No. i to the valve Xo. 2 on the 
oxygen drum. Then attach the black oxygen hose to the regula- 
tor and the upper valve No. 3 on the torch. Connect the acetylene 
regulator No. 4 to the valve No. 5 on the acetylene drum. Then 
attach the red acetylene hose to the regulator and the lower valve 
on the torch. I'nscrevv the regular handles Nos. 7 and 8 until 
they do not bear on the spring inside. This will close the regu- 
lators and i)revent the passage of gas when the drum valves are 
opened. Now open the drum valves 2 and 5, and the torch valves 
3 and 6. Screw in the handle on the acetylene regulator until 
the gas begins to flow and adjust the flame, as will be described 
in Chapter No. ii. The apparatus is now ready to use for 
welding. When not in use the connections may l)e left intact 
with the valves closed. 

Portable .Icctylciic Generator: — A portable generator plant 
is provided for welders who prefer to take advantage of the 
saving that may be effected by generating their own acetylene. 
The plant consists of a generator of 25 or 50 pounds capacity 
mounted on a four wheeled truck with two ox\gen drums and 
usually provided with a tool box for supplies and small apparatus. 
One of these plants is show^n in figure No. 28. It will be connect- 
ed and operated much the same as the plant just described excei)t 
that the acetylene regulatr)r will of course Ix" attached to the gen- 
erator instead as directed in the previous paragraphs. 

Two colored hose are provided to distinguish between the 
oxygen and acetylene, and it is recommended to use the black 
hose for the former and the red hose for the latter. 

Regnlatiiii^ the Charge For Weldings — Purchasers of weld- 
ing outfits are immediatelv confronted with the ])roblem, of how 
to adjust their charge for services, to conform with the usual 
practice. 

To give explicit directions for making charges would be 
useless, the location of the plant with references to neighboring 
towns, shipping facilities, the comparative cost of labor and 
commodities, the risk attending the work, the urgency of the de- 
mand, the cost of a new piece to replace the broken one and the 
cost of gases including freight and cartage, are all factors to be 



84 



OXY-ACETYLHXE WELDING AND ("UTTlXCx 



considered in determinin*;- a just charge. A knowledge of how 
these factors enter into consideration is best conveyed to the be- 
ginner by ilkistrations. 

As a rule it is advisable to make a minimum charge, which 
may range between 75 cents and $1.00. This, however, can not 
be rigidly adhered to. 




Fig. 28 

roTrPABEK (;exi;kator plant 



If the welder has his torch lit and can conveniently leave his 
work for a few minutes to weld a job of comparative insignifi- 
cance, a charge of 50c might be both just and profitable, but if 
the weld is to be made on the knotter of a binder, the charge could 
justly be proportionately higher. For instance if the selling price 
of the piece is S5.00 and the express charges 40c, the actual cost 
t)f a new piece would be $5.40. The time required to get this 
piece from the dealer, might be two days, during, which time the 
binder would be out of commission. If in welding the old piece, 
the welder uses 75c worth of gas and one hour's time at 35c it 



OPERATING PLANTS S5 

would actuallv ci)>t him Si.io to do the work but in this instance 
lie would be amply justified in a charge of $4.00. 

To determine the actual cost of work one would proceed as 
follows. Two drums, one hundred feet each at 2c per foot, would 
cost $8.00. to this would be added freight and cartage, which 
might come to $1.00. making a total cost of $9.00 for 400 feet or 
2 '4 cents per foot. The acetylene, if purchased in drums, would 
be calculated the same way ; but if it is generated in the shop, one 
would consider the cost of carbide. One hundred ])()unds of car- 
bide at 3;y4C comes to $3.75 plus 40c for freight and cartage 
makes a total of $4.15 per hundred pounds carbide. This will 
generate 450 feet of acetylene which ])uts the cost of acetylene at 
about 9-10 of a cent per foot. 

From the table, in the back of this book, may be learned the 
amount of each gas the various sized tips, used during one hour 
of continuous burning. To find the cost of gas, used on a job, 
would simply reciuire multiplying the quantity used per hour by 
the number of hours in use, and that, by the cost per foot. 

To do a certain job of welding, we will suppose it required 
3 hours time. <)() feet of oxygen, 87 feet of acetylene, 10 pounds of 
charcoal, and one pound of welding rod, and it is desired to figure 
the cost. A tyjjical procedure would be as follows: 

3 hours time, at 35c $ T.05 

i)0 ft. oxygen, at 2 '4c 2.02 

87 ft. acetylene, at ic 87 

$ 3-94 
Double for ii\er head charges 2 

$ 7.88 

I 11). welding rod, at loc to 

10 lbs. charcoal, at !c 10 

Total cost $ 8.08 

50% ])rotit I m work .• . . 4.04 

Charges for work $12.12 

The purposes for doulTling the cost of labor and gases for 



86 OXY-ACETYLENE WELDING AND CUTTING 

overhead charg^es. is to cover the cost of maintaining- and operat- 
ing the shop, inchuHng rent, heat, Hght, insurance, bad ac- 
counts, etc. 



OXVGEX ACETYLENE WELDING C(J. 
TIME CARD 

Job. Xo 

Date Tag Xo 

Workman Tag No 

Tag No 

Tao- No 



I Irs. 1 .abor 

I Irs. C )\crlime 

Ti]) Xo ilrs. 

'V\]^ Xo Hrs. 

Ilrs. Oil Torch 



Lbs. Charcoal 

Lbs. Asbestt)s 

L])s. .\sbestos Cemenl 

LI)s. Cast Iron 

Lbs. Steel 

Lbs. -Muminum 

Lbs. llronze 

Lbs. Copper 

Misc. Material ... . 



Description of work 



Fig. 29 
COXYENIENT Tl M K CAKI) FOl? WELDING SHOPS 



chapti-:r X. 

WELDIXG RODS AND FLUXES. 

llic Theory of Fhi.vcs: — Fluxes are used to clean the sur- 
faces ot the metals, to remove or ]irevent the accumulation of 
im])urities hy unitini;- with them hefore the\- combine with the 
metals, and snmetimes, to lower the meltinj^- tem]K'rature. The 
action is ])urely a chemical one and the task of ]irei)arinL; i>r ])re- 
pariuiL;- or prescribing- suitable thixes for the A.arious metals, 
should on]\ be uudertaken l)y one who is thorou,uhl\- familiar with 
their chemical reactions. 

The physical and chemical i)roperties of the \arious metals 
are so differeut that a tlux which would be suitable for weldin_y 
one material would be ruinous to another. To illustrate. ])hos- 
phorus contained in copper alloys, increases their strength and 
toughness; btit one tenth of one per cent in steel causes it to be 
very brittle. J'hosphorus has a great attinity for oxygen and 
when incorporated in melted copper, it will unite with the ox\- 
gen which tlie copper absorl)s. and burn out taking the oxygen 
with it ; but with iron, for which phosphorus has a greater aftinitv. 
this is different; when phos])horus is incor])orated in melted iron 
it does not combine with ox}gen. but remains in the ir<»n and 
makes it brittle. 

The Theoretical t1tix f(tr each of the metals would be a sub- 
stance that would combine with the gaseous im]:»urities which are 
l)rought in contact with the melted metal, and after combining, 
will be liberated and jxass ott as a gas. or form a slag that will 
lloat on the surface. Since the service of a dux is in chcmicalK- 
uniting with objectionable ini])urilies and remo\ing ihem, and 
since this chemical union can only occur in a deiinitc proportion, it 
follows, that if more dux is used than will chemically imite with 
the element to be removed, il will be free to luu'te with something 
else and become a new objeclion. b'or this reason lluxes should 
l)e used strictl}- in accordance with the instructions given I)\- the 
manufacturers. 

The gaseous impurity, usually combated 1)\- duxes is oxygen; 
but in st)me metals, such as. copper. l)r()nze, and ahuninum, 
there are other gases that may be absorbed unless their absorbtion 
is pre\enled by the presence of a suital)le tlux. In instances of 



88 OXY-ACETYl.EXK WELDING AND f'T'TTINC 

this kiiul tlie formula tor the fluxes, are sometimes quite compli- 
cated and to avoid the excessive use of certain chemicals they are 
frequently incorporated in the welding' rod. Then by using these 
rods with the fluxes designed for them, the gases are C(^mpletely 
absorbed and eliminated. 

To weld 7cr<)Ui^J}t iron, stcrl castiiii^s. steel plates and foi'i^- 
iiii!;s, no flux should he re(|uired ; but a special steel welding rod 
is furnished in wliich the metaloids are combined in the right 
proportion to gi\e the best results. 

Cast Iron re(|uires a tlu.x to destrox the oxide, which is less 
fusible than the metal, and which interposes itself in the welds and 
prevents the perfect joining of the molten metal. The action of 
the flux is to lower the melting temperature of the iron oxide, 
which will then Moat to the surface where it may be removed. 

The welding rods should be selected according to their sili- 
con content. The right proportions of silicon tend to eliminate 
the oxide from the iron. 

Coppers — When copper and the copper alloys are melted 
thev absorb oxygen, hydrogen, and carbon dioxide gases and to 
combat these gases is a problem that has not been solved imtil 
recentlv. The first attempts to absorb these gases into flux re- 
sulted in changing the texture of the weld: but today the manu- 
facturers are supplying a flux to be used with a special welding 
rod. and the results obtained with them are eminently satisfac- 
tory. 

It follows from what we have just explained, that the manu- 
facture of welding materials containing deoxidizing elements, is 
extremelv delicate, and necessitates rigorous supervision and con- 
trol. 

Welders who use the oxy-acetylene process in manufacturing 
and repairing, are by no means disposed to analy/.e or examine 
micrographically, the materials they are putting into their 
welds, and since these precautions are necessary to the production 
of reputable welding materials, it is w^ell to shoulder the respon- 
sibility on a trustworthy manufacturer whose success depends on 
your success. 

The selection of rods and fluxes for the dift'erent metals will 
be treated fully under the subject of welding. 



89 
CHAPTER Xr. 

GENERAL NOTES OX WELDING. 

Time used in prepariiit,^ for the weld is well spent. In a few 
days, a welder can acquire sufficient .skill in handlino- the torch, to 
perform a fairly g-ood weld, under favorahle circum.stances ; but 
to do equally good work under any circumstance, requires 
thought, study and experience. 

The priiuary object is to secure a weld that will he homc- 
i^-enous in texture, free from blow-holes, hard sjjots or scale, void 
of internal strains, and to leave the piece free from distortion. 
The first three features mentioned are obtained in the actual per- 
formance of welding-, and will be treated fully in a later para- 
graph, but to leave work, void of strains and distortion re(|uires 
preparation in the way of ])reheating. 

Clcaniiii:;: — It is unnecessary to s])end much time in ck'aning, 
scraping, or brightening the ])art to be welded, as woidd be re- 
(|uired for brazing or soldering. The only requisite in this line 
is to remove the mud or grease by wiping. Other impurities burn 
or are melted and float to the surface where they may be scraped 
oft with a rod. 

Hc-c'cliiii^-.' — If the piece to be welded is thicker than y(i, of an 
inch, some time and advantage may be gained by beveling the 
edges, to enable the llamc to entci- between them, .-md the weld 
started at the bottom and built up. In pieces thinner than j/s of 
an inch, it is only necessary to sej)arate the edges about 1-16 of an 
inch, to obtain the same advantage. If the pieces are verv thin, 
like sheet iron of 14 gauge and lighter, they are liable to give 
some trouble by warping and buckling, and as the welding con- 
tinues there may be a tendency for them U) overlap each other. 
If this overlapping is permitted it will not only make the operation 
of welding more difficult, but it wall destroy the intended shape 
of the article being welded. The operator should, therefore, care- 
fully watch that the edges do not overlap, and if they can be bent 
up at right angles to a height of 1-16 of an inch it will make the 
work much easier. The bent uj) edges are melted and furnish 
welding material. 



90 



OXY-ACETYLEXE WELDIXG AXD (TTTIXO 



The amount of advantage gained in beveling, dei)ends on the 
thickness of the piece, and the method of beveling. The object 
being to enable the operator to melt the material in the bottom and 
sides of the fracture and fill the gap with new material melted 
from the end of the welding rod. To secure a tborough and 
strong job, it is easily understood that ibis ])n)cess must iuclude 
the whole fractured surface, otherwise there will be a portion un- 
welded. and unless the edges are cut away or beveled, it will be 
necessary to melt the material and blow or scrape it out. to be 
certain tbat the welding includes the entire fractured surface. 
Fig. 34 and 35 show the method of beveling i)ieces y^ inch to j4 
inch thick. 




PRACTICAL M 



Figures 34 and .35 
MIOI) OF BHYEEINC THIN I'lKCKS 



In work of this kind it is practical to bevel one side only : Init 
in thicker material, if access can be had to the reverse side, a 
saving mav be obtained by beveling both sides as shown in Fig. 

This can not always be done, for the reverse side may not be 
accessible ; but the work and expense is reduced about one-half and 
there is greater assurance of a thorough weld, when the work is 
done from both sides. The beginner is very liable to sacrifice 
good work for neatness and appearance. It is much easier to do 
a neat looking job by simply welding on the surface; but this 
])ractice is positively to be condemned, and although a deep weld 
may look scattered and irregular the beginner should train him- 
self until deep welding becomes instinctive or habitual. 



GENERAL NOTES ON WELDING 



91 




MKTHOI) OF BEVELING THICK I'lECES 

A weld which is nuulc from l)()th sides will look neater hecause- 
the hreadth of the fused surface will he narrower, and it can l)e 
more (|uicl\l\- fmished. hecause the area of the cross section 
throuj^h the weld is only half as Li'reat, conse(|uently there is only 
half as much metal to melt and till in. 'Jdiis is more clearly illus- 
trated in l'i,ys. 37 and 38. 





Fiiiuros Ml and oS 
JLLl'STK'ATJNG Til K KCONOMV OF BFVELING ON BOTH SII)1> 

m which the area is divided into triangles having ccjual area. 
This illustration is self exi)lanatory, it heing necessary to merel\ 
coimt the number of triangles in each figure, to ascertain the 
com])arative areas. 

/'rccaiitioiis Jx'ci^^ardiiii:; JLvjnnisitur. — The phenomenon of ex- 
])ansion is exi)lained on i)age 32 under the chapter on ])hysics, 
and it is here proposed to explain to the welder, how this ])he- 



92 



OXY- ACETYT.EXE WKT,DTXG AND (TTTIXG 



nomenon may effect his success or defeat according' to his under- 
standing, and preparation to provide for it. 

When metal is heated it will expand and there is no evading 
it. Sometimes trouble occurs when expansion is taking place. 
At other times it does not develop until after the metal com- 
mences to shrink, or resume its original proportions. The re- 
sult of expansion and contraction often produces the most unex- 
jiected effects, and the welder is admonished to give this subject 
much earnest thought. No text book can tell him what may 
happen or what to do on every occasion that may develop during 
his welding career; these are things that must be studied out 1)\ 
himself, and his ultimate success depends as much on his ability 
to overcome the effects of expansion as on his ability to handle 
the torch. So do not pass this subject until you are thoroughly 
determined to observe, study and solve the capers that expansion 
will play with you during your earlier efforts. Sometimes the 
effect of expansion can be ignored, and the welder \\\\\ soon 
learn bv experience, when this will be true. .\ good illustration 
of this is in figures 39 and 40. 




2^— '- 

Fijiurrs :;SI uii.l W 
KFFKCTS OF FXI'AXSTOX AXD COXTKACTIOX 



In Fig. 30, no bad effects of expansion are to be feared be- 
cause the ends are free to move and extend or withdraw. On 
the contrary in Fig. 40 the same bar having the same break, is 
the center member in a two panel frame. What will be the eft'ect 



GENERAL X0TE8 OX WKLT^ING 9:t 

of expansion in this case? As the metal in the vicinity of tlie 
weld becomes heated it will expand. The ends being a part of 
the frame at 3 and 4 will be held in their normal position ; but 
the melted portion surrounding the weld will offer no resistance, 
and the expansion will i)ush the melted ends closer together in 
the weld. When the job is finished, and the metal begins to 
cool otT. shrinkage takes place and the center bar shortens. Tf 
the metal is elastic or ductile the shrinkage may not cause a 
break, but will cause a strain or deformation of the frame. This 
would probably be the case with mild steel; but with cast iron, 
it would likely cause a break in the hottest place, which would be 
in the newly welded portion. Xeglect to provide for expansion 
would therefore cause failure. 

Copper, alumimun. cast iron, and those metals that are weak- 
est when hot, will usually break in the weld. 

( )n rcHection. it will be observed that, to make a success 
of this job. it is only necessary to preheat the portion of the 
frame, indicated at i and 2. then on cooling the shrinkage will 
be ecpial in each of the parallel bars, and no break or distortion 
will result. 

If it is impossible to heat the frame, as described al)ove. other 
methods are at the disposal of the welder; for example, a slight 
spreading of the two bars 3 and 4. to the position indicated In 
the dotted lines. 'J1iis may be done with keys, wedges, or jack- 
screws, and the efifect is to separate or spread the fracture. 
While making the weld. ex])ansion takes place, as described be- 
fore : but when the weld is finished and shrinkage commences 
the wedges or screws are removed, and as the center bar shortens, 
tlie sides graduallv resume their former i)osition, and the frame 
is \-oid of strains or fracture. 

.\nother method, which is not especiall}' recommended ex- 
cei)t on rare occasions, is to cut the frame at 5, then weld the 
fracture and the cut will acconnnodate the expansion by spread- 
ing, then after the center bar has been welded and shnmken, 
the cut in the corner can be welded, where the cft'ects of ex- 
pansion and contraction need not be feared. 

There has recentl\' come into use. a method of restricting 
the expansi(^n to a verv limited portion, resulting in the ex- 



94 OXY-ACETYLEXE WELDIXG AXD CUTTJXG 

pansion being- so slight that it may be ignored. This is done 
by allowing the portion immediately surrounding the weld, to 
attain the required temperature ; but preventing the heat spread- 
ing, which of course will reduce the expansion, by cooling the 
surrounding portion with water. 

If restricting the amovuit and extent of expansion is all that 
is to be desired, this method might give satisfactory results: 
but there are other causes that may produce failure. One of 
these is chilling the metal. For reasons that will be explained 
later it is desirable to have the weld and surrounding metal 
as liot as it can be made without changing its shape, or texture, 
and if the cooling method is used to eliminate expansion, the 
heat of the portion being welded, W'ill be conducted away, and 
it will be impossible to maintain a temperature that will give 
the best results. 

The Economy of Preheating: — Preheating is essential as an 
economic measure. To properly execute a weld, the sides and 
bottom of the fracture must be melted, and if the metal is cold 
it will re(|uire more of the welder's time, and more gas to bring 
it up to the melting temperature, than if it had been ])reviously 
heated with a cheaper fuel in a manner that did not require the 
constant attention of the operator. Therefore, to obtain the 
greatest measure of economy, the piece to be welded should be 
placed in a preheating furnace, and allowed to heat up while 
the welder is doing something else. 

Preheating to Eliminate Defects in the U'eUT. — It has been 
explained under the chapter on metallurgy called "Metals and 
Their Properties." that, when melted cast iron or high carbon 
steel comes in coiUact with a cold metallic surface, it chills and 
becomes so hard that it cannot be machined or filed. It is not 
an uncommon thing to find hard spots in a cast iron weld, which 
have been caused in this way. 

Cast iron contains more impurities than any of the ferrous 
group, and when it is melted, these impurities form a gas and, 
if the metal is sufficiently fluid, they will float to the surface in 
bubbles and be liberated ; but if the melted metal is not per- 
fectly fluid, these bubbles will remain in the bath and show blow 
holes in the weld. 



GEXKRAL XOTHy OX WELDING 95 

In lieavy sections of cast iron that have not been preheated, 
the melted metal is chilled so rapidly by the surrounding cold 
portion, that it cannot be kept sufficiently fluid for these gas 
bubbles to raise. 

Considering the foregoing it may be said, that the ])ractice 
of preheating cannot well be eliminated. 

Hcrw and Where to Preheat: — An article like an automobile 
cxliuder or motor frame should be heated throughout, so that 
the whole ])iece will be hot and expand in all directions alike. 
This is also true of any other small intricate piece that may 
become badly distorted or broken 1)\- unequal expansic^n : but in 
the case of a large flywheel or gear, with one or two broken 
spokes, it would be cumbersome, expensive and unnecessary to 
preheat the whole wheel. 

T.arge articles of this nature are only preheated in a portion 
which must be selected according to the location of the break. 
This ])orlion will usually include the hub and a little over one- 
half of the rim. including llie broken ])ortion. The preheating 
furnace for thi^ kind of work will be a temporary afl:'air built 
of looselv ])iled l)rick. with an asbestos covering. One side is 
semi-circular, and follows the contour of the wheel, and the othei 
side is straight, fitting around the spokes and rim. The arrange- 
ment of air drafts nuist accommodate the nature of the work. 

. hi j list i lit:; tlie l-laiiie: — (Jne of the tir>t things the welder will 
note, is the i)eculiar appearance of the tlame issuing from the 
ti]) of his torch. When this is in normal working condition there 
will be an inner white llame of dazzling brightness, surrounded 
bv an outer tlame of a pale bluish tinge, with a wide yellow- 
border. When this iiuier flame is at the maxinuun size attainable, 
and has a clear distinct outline, the flame is said to be neutral. 
That is. it will have neither an oxidizing or carbonizing eft'ect 
on the weld. With very few excejitions. this is the kind of flame 
that should be obtained before starting to weld. Manipulating 
the valves to i)roduce this kind (»f flame is called adjusting the 
torch. The method of ])roce(hn-e. to attain this adjustment, is 
ilescribed as tollows : 

After connecting the torch and regulators as described in 
chapter 8. the operator will see that all valves are open except 



96 OXY-ACETYLENE WELUIXG AND ('I'TTSXG 

those in the ret^ulators. these will he closed hy unscrewing the 
handle until it is quite free and does not hear on the springs 
within. Starting from this i)ositi()n the oiK-rator will screw in 
the handle on the Acetylene regulator until the gas begins to 
flow, and then ignite it. C\)ntinue to screw in the valve handle, 
imtil the base of the tlanie ap]iears to leave the torch and stand 
away about an eighth of an inch. 

The acetylene flame is now a large, flaring, smoky, irregular 
shaped mass: but screw in the handle <m the crvi^i'// regulator, 
and the tlame will commence to assume definite size and propor- 
tion. Continue to slowly open this valve and there will ap])ear 
an inner white flame that blends with a thin feathery edge into 
a ])ale blue outer flame. 

.\s the oxygen supjily is increased, this inner white flame 
becomes smaller and the outline more distinct and, when this 
thin feather\- e(\ij:;e is entirely gone, the imier flame will be about 
three times longer than in diameter, and have a distinct outline. 
This is a neutral flame, and is the proper flame for welding. 

Handling the Torch : — Having the edges of the metal beveled 
as described before, and placed parallel, the flame of the torch 
is directed into the \' shaped groove formed by the bevel. Tlie 
metal on the sides and bottom of the groove is melted until it 
is quite fluid, then the end of the welding rod is l)niuglu under 
the flame and when it commences to melt it is submerged in the 
metal melted from the sides of the groove. 

The flame and welding rod are kept continually in motion, 
the rod following clo.se behind the flame, repeatedly dodging in 
and out from under it with a little circular motion; but always 
submerged in the melted metal and always hot enough to be 
continuously melting and feeding the weld with new material. 

The torch wdll be advanced along the line of the weld just as 
fast as the sides and bottom w'ill melt, and become thoroughly 
fluid, while the frequency of the circular movements of the rod 
and the length of time it remains under the flame, will be timed 
to fill the weld as fast as the torch advances. The flame and 
rod should always be together. 

At first the welder will be bothered by having his welding 
rod freeze to the weld, which will have to be melted loose again 



GEXERAL XOTP:s OX WF.LDTXG 



97 



with the torch: hut he should l)e undaunted hy these httle events 
for they only serve to remind him that his welding- rod must 
alwa\ s he melting hot and submerged in melted metal. 

It takes practice to acquire the knack of having the torch 
and rod continually in motion describing little circles, keeping 
them close together, regulating the melting rate of the rod to 
fill the w^eld as fast as the sides of the groove are melted and 
become tit to receive new material : but the knack is acquired 
with only a few days of ])ersistent effort. 

The melting of the welding rod and the edges of the weld 
must take place at the same time, and the rod stirred in the puddle 
of melted metal, to make the two metals alloy immediately wit'- 
each other. 

If the rod tlows between the edges of the wel<l before the. 
are melted, the weld will be bad. 

The melting rod should never fall in drops on the weld. 




TlIK MKI/riNd K'Ol) SIl()ri>l) NOT DHll' l.XTU Till-: WKl.D. 



The torch should be held so that the end of the white tlame 
is ''8 to Yit. of an inch away from the work, the distance lieing 
proportional to the size of the tip and the nature ai the work. 
For a medium sized Up a good average distance would be '4 of 
an inch. P^xtreme care must be taken to not ^XMUiit the cud oi 
the ti]) to touch the melted metal, or to allow the melted metal to 
s]ila^h into the tip. 



98 



OXY-ACKTYLENR WELDING AND CUTTING 



Movements of the Torch : — An advantage may be gained by 
giving the torch a sHght circular movement to (hrect the tlame 
rotativelv against one side oi the weld, back onto the welding 
rod, over to the other side of the weld, then forward onto the 
unmelted portion and thus continue in a series i>f little circles, 
of uniform size and regular fre(|uency. The diameter of the 
circles should be nearlv eriual to the l)readth of llio weld. 




Fig. 42 

('IKM'[-LAK MOVK.M K.NT i)V TORCH FOR WORK OF MKDIUM 
THICK XKSS 



lu>r welds of greater thickness a side to side movement may 
give better results. The amount of the movement correspond- 
ing with the breadth of the weld, and regulated in time to the 
melting of the sides. These movements are however only sug- 
gestions, and the welder nnist decide for hini'-elf what course 
he will pursue. 



GEXEEAL NOTES ON WELDING 



99 




SIDK TO SIDK MOVK.MKXT OF TIIK TORCH ?^0R HKAVIKK WKLDS 



There are certainly manipulations to be learned, but they 
are relatively easy to acquire, and are better obtained by practice 
than by reading". 

The beginner usually does not melt enough and the weld 
lacks penetration, or he melts t(M) much, and so makes holes. 
It is evidentK necessary to tliid a ha]ipy medium, and al>ove all 
to work regularly. 

F/7//H_i[ /';; Holes: — Holes arc particularly despairing to the 
beg^inner. because in trying to mend them, he usually sees them 
enlarge. A few instructions on tilling these holes will be appro- 
priate here. The flame should be inclined until it is almost 
parallel with the surface of the work and directed against the 
edge of the material. As soon as the metal begins to get plastic, 
a little metal is welded to the edge, from the welding rod. Con- 
tinue this process until the hole is filled. The principal difficulty 
encountered in this work is to regulate the heat so that it will 
not melt the edges away or cause the welding rod to drip through 
the opening. 



100 OXY-ACKTYI.?:XK WKLDTXG AND CUTTING 

/ 




Fii:. 44 
I'OSITIOX OF TOl.M'II FOIx" Fll.LIXC TIOLKS 

Dcfccfs of Welds: — During- the i)rocess of welding- there are 
several defects that may develi>i) and to a\oifl tlieni the welder 
is admonished to he constantlx alert to the canses that ma\- ])ro- 
(hiee them. 

The first, is lack of i)t'netration. This more frecjuently takes 
l)lace when the edges of the weld are not heveled : the heat has 
not been stifficient to melt through the metal, and the original 
crack shows on the reverse side. This not only effects the solidit}- 
of the weld, but affords a starting pt^int for a new break. 

To avoid this defect, one must not go to the other extreme 
and melt holes through the piece, for these holes cause loss of 
heat and time, and assist oxidation. 

Next there is adhesion. This very significant term is difficnlt 
to explain. One obtains adhesion in different ways, either by 
not sufficiently melting the edge of the weld, or by doing so un- 
equallv. It mav also be done by flowing melted metal onto parts 
that have not been previously melted, or have cooled off, and 
again by inter])osition of oxide in the bath. 

Welders should exercise constant care to avoid ""adhesion'' 
for it is not rare to find this defect in welds made l)y experienced 
workiuen. ^Melted metal flowing from the edges of the weld 



GEXEEAL NOTES OX WELDING 101 

into the bottom, will cause the same defect, if the bottom i> not 
melted. 

There are sometimes bad joints due to the interposition of 
a layer of oxide between the old and new metal ; this is gen- 
erally due to piliuo- melted metal on metal that has solidified, 
or to lack of liquefaction in the molten bath. 

l)low holes frequently form in the weld and the stren,<^th 
of the joint suffers accordinoly. These blow holes may be due 
to lack of i)reheating;, to absorption of sj^ases. or to blowing air 
into the melted metal with the torch. The elimination of the 
first two defects will be treated under the subject of welding the 
different metals. 

We nuist mention lastly that welds are sometimes insufficient- 
ly filled. The level of the weld does not reach the surface of 
the piece. Such defects are attrilnited entirely to carelessness. 
IVcldiiii^ Wrought iron and Mild Steel: — Wrought iron and 
mild steel are the easiest metals to weld by the autogenous i)roc- 
ess. They recpiire no ilux to absorb oxides or i»ther impurities. 
A steel welding rod is used and by following the instruc- 
tions given in the preceding paragrai)hs of this chapter, the 
welder is provided with all the instructions he may re(|uire. The 
only other thing needed is practice. 

Welding Cast Iron: — When everything is taken into con- 
sideration, the difficidties to be overcome in welding cast iron, 
are neither numerous or iusunuountable. as a matter of fact 
when cast iroii is projierly welded the joint is stronger than 
the original ])iece. This is generally due to the sujjcrior (|ualit\- 
of the iron ])ut into the weld. 

In the chapter on metals and their properties, we learned 
that cast iron contained a large amount of carbon. That this 
carbon existed in the cast iron in two conditions, that is. the 
combined condition as white iron and in the free or graphite 
condition as gray iron. We also learned that the gray iron was 
soft and that the white iron was very hard, and could not be 
machined. 

Since the majority of welds in cast iron should l)e capable 
of being machined, it is indisiiensable that the weld should be 
in the condition of grav iron. 



102 OXY-ACETYLENE WELDING AND CUTTlXCi 

When welding rods of j^roper consistency are used, a good 
soft gray iron weld can be obtained by protecting it against 
chilling while the melted metal is being run in. This may be 
done bv preheating and pursuing the methods prescribed to pre- 
vent adhesion. 

Cast iron requires a flux to destroy the iron oxide, wliicli 
is less fusible than the metal and which inter])oses itself in 
the weld and i)revents the perfect joining of the molten metal. 
The action of the tlux is to lower the melting temjierature of 
the oxide, which will then float to the surface where it may be 
removed. The flux is used by putting the end of the hot welding 
rod into the box of flux and then working it into the weld. 

Cast iron is ladeu with imi)urities which form gases when 
the iron is melted. If the melted iron is kept sufficiently fluid 
these gases will come to the surface and disa])])ear. but if the 
uietal is iu oul\- a semi-thiid state they will remain in the l^ath 
and cause a s])ongy weld. This trouble is more noticeable in 
heavy work, which, if not preheated, will chill the melted metal 
so ([uickly thai the gases cannot escape. 

The elimination of these gases may be assisted 1)\' rotating 
the torch around in a little pool and then gradually withdraw- 
ing it: l)ut in so doing the welder should be careful to not blow 
air and gases into the melted metal. Thoroughly jjreheating 
the casting will also greatly assist in eliminating the blow holes. 

irddlno; Malleable Cast Iron: — While the process of auto- 
genous welding is being used so successfully in all the metal 
trades, many unsuccessful attempts have been made to weld 
malleable cast iron, and to those who have experienced disap- 
]X)intment. an explanation ni wh\- their efforts failed, with an 
outline of a method by \\liich these castings can be mended, 
should be of benefit. 

Malleable castings are first made in the condition of hard 
brittle, white cast iron and subsequently made malleable by 
heat treatment. The heating process w'hich converts white cast 
iron to malleable iron is called annealing, and effects a chemical 
change in the structure by decarbonization. This dccarbonization 
is nearly com])lete at the surface and penetrates in a lessening 
degree toward the center, giving the outside portion the texture 



(JHNEKAL NOTES OX WELDING 103 

of mild steel while the inner ])()rti()n may retain, in a more or 
less (le,qree. the ([nalities of cast iron. When this metal is re- 
melted the carl)(>n is dispersed, and the entire mass reverts to 
cast iron. 

The o])erator who is used to weldinq- mild steel and cast iron 
will recall that they are handled dift'erently. That the method 
used in welding- steel to steel would he useless in welding; cast 
iron, or the methods emi)loyed with cast iron would he equall\ 
unsuccessful with steel. That is ])ractically what he is tryini^ 
to iU> when he undertakes to weld a malleahle casting'. The 
material is not homogenous. The bottom ])ortinn of the weld 
being' in cast iron, and the to]) portion in steel, with no definite 
dividing line between, it is useless to follow tlie method prescribed 
for either, and to his trouble is added the difficulty occasioned by 
the diffusion of the elements in the materird melted from the 
sides of the fracture. 

It follows that to successfully mend a malleable casting the 
process employed must not necessitate melting" the sides of the 
fracture, that the welding- material should fuse at a lower tem])er- 
ature than the casting-, and that its adherence, bonding' (|ualilies. 
phvsical strength and ductilit\' should closely resemble the original 
casting-. After much stud\- and e.\])erimenl. the N'ulcan Process 
Compau}- and their allied interests in Minneajxilis are having- 
considerable success in mending broken malleable castings, and 
a descri|)tion of their methods will uncloubled]\- be useful to 
others who are em])loyed in the metal trades. 

In pre])aring the work for mending', the fracture is chij)ped 
awa\' in the form of a \ groove with the ])ointe(l bottoiu just 
coming to the surface on the o])posite side. or. if the casting- 
is thick rmd the opposite side accessible, two grooves arc cut 
with their ])oinled bottoms meeting in the center. The ))art 
surrounding- the fracture is then heated with an oxy-acetylene 
torch to a bright red. and si)rinkled with \ nlcan bronze flux 
followed bv a few drops of Tobin bronze melted from the weld- 
ing- rod. If the bronze remains in a little g'lobule the work is 
not hot enough, but if it s])reads and adheres to the surface, the 
temperature is right, and the groove shoidrl be quicklv filled. 
It is nc^t acKisable t<> keep the work hot anv longer than is ueces- 



]04 OXV-ACKTVI.KNK WELDING AND CUTTiXG 

san'. but to make the mend as quickly and at as low a tempera- 
ture as possible. The behavior of the bronze affords a i^^uide 
in res^ulatiny- the leni])erature. 

This process cannot be called autooenous welding-, but a mal- 
leable casting mended in this way is practically as good as one 
piece. It has about the same tensile strength and duclilitx as the 
original and the process has the ad\antage of being very (|uickly 
performed. 

]Veld'nr^ Copper. Brass and Bronze: — Co])per and all of its 
allovs have a facult\ of al)sorl)ing gases from the t1ame. The 
oxide of co])per is very solul)lc in the metal and forms, with it, an 
alloy which crystallizes in the mass and destroys the homogen- 
eous le.xture of the weld. 

If the autogenous welding of copper is obtained by melting 
the edges and adding metal melted from a pure copper welding- 
rod, there will necessarily be considerable oxidation of the metal 
and the oxide will remain in the weld. The metal will lose its 
distinctive properties and be riddled with blow holes. Xo ma- 
nipulation or regulation of the torch can overcome these defects. 

It is therefore necessary to use a deoxidizer capable of re- 
ducing the oxide as it is formed. Since the oxide is dissolved in 
the metals itself, the use of a flux does not give the expected re- 
sults. It is therefore necessary that the deoxidizer be incorpor- 
ated in the welding rod, so that it will be diffused continuously 
throughout the molten metal. All welds made on red copper, 
without the use of deoxidizing welding rods, are therefore 
strongly oxidized and full of blow holes. 

The tensile strength of copper diminishes rajiidly as the tem- 
perature is raised and unless the welder uses precautions to re- 
lieve the weld of strains while it is hot. it will be very likely to 
crack. These strains may be relieved by heating other parts of 
the piece. 

The weld should be prepared exactly the same as for weld- 
ing iron or steel, and the torch manipulated the same as described 
before. 

( )n account of the conductivity of this metal, it might be ad- 
visable to use a larger tip, on the torch, than would be used for 
welding steel. The flame of the torch should be perfectly regu- 



GKNKKAL NOTKS OX WELDING 105 

lated and maintained without excess of either gas, for if either 
acetylene or oxygen is free in the flame it will be al)sorhed in 
the weld. 

r)rasse> and l)ronzes require the same precautions and weld- 
ing rods as are used for copper; but on account of their con- 
taining other metals, it is necessary to use a bronze Hux in addi- 
tion Id deoxidizing welding hkIs. 

U'cUiiiti:; . Uitiiiiiiuin : — When aluminum is melted it oxi- 
dizes ver\ freely and this oxide which clings to the surface of 
the metal, prevents the joining of the new metal to the old. It 
is therefore necessary to remove this oxide, which is done by 
scraping it out after the metal is melted. .Muminum melts 
at a comparatively low temperature and. since the welder is 
iu)t warned of the approaching melting temperature. 1>\- any 
change in color, he nnist use care not to melt the whole struc- 
ture and destroy it. This may occur in the jireheating hre un- 
less caution is used. Aluminum like copper is very weak when 
hot and this property combined with the excessive ex])ansion of 
the metal, is something that may cause the weld to break soon 
after its completion unless precautions are taken lo remove 
shrinkage strains, by ])reheating. 

Some writers advocate the use of a deoxidizing tlux for 
making aluminum welds; but others believe better welds may 
be obtained by the "puddle" system of welding than 1)_\- the use 
of lluNcs. It is the writer's observation, that excellent welds are 
being made today by the i)uddle system, and since this method is 
very easily learned, it will be described here. 

The ruddle System: — Aside from the oxy-acetylcne torcli 
and welding rods of the purest aluminum, the only tool used is 
a long slender steel rod. flattened on the end to form a paddle 
or spoon. This rod is called a sjxatula. Armed with this tool 
the welder will melt the metal where the w'eld is to be made 
and with the spatula, scrape off the surface, leaving it clean and 
bright. This only removes the dirt for. although it may not be 
visible, oxide forms on the bright surface immediately behind 
the s])atula. and unless it is bntken up the new metal will not 
]o\u. Breaking up this oxide is done after the surface is covered 



10(5 OXY-ACETYLENE WELDING AND CUTTING 

with new melted metal, which protects it from further oxida- 
tion and is accomplished by o-ently scraping the spatula thnnigh 
the mass of melted aluminum and removing" it. 

The operation is somewhat similar to scraping the skin oif 
melted babbit : the only difference being, that the oxide of 
aluminum ma\ 1)e mixed with the melted metal. The success 
of the weld depends en the tboroughness of this skinning or 
puddling operation. 

After a little metal is added and thoroughly puddled, more 
aluminum is melted in and the ])uddling repeated. 

Tlie precautions to be taken in welding aluminum are sim- 
ilar to those described before. It is of ])rimar\ importance to 
never add new metal to a surface that is not in a molten condi- 
tion. 

Lead /)//;-///;; 1^ : — The process called burning is used for join- 
ing the edges of lead sheets or pii^es without solder. The edges 
are fused to an extent which ])ermits the ])arts to unite and form 
one solid ])iece when cooled. This i)rocess is known as the auto- 
genous process, and although it has been practised for centuries, 
it is used far less at the i)resent day than it should be. It aff'ords 
a (piick and cbea]) method of making lead joints of the most 
durable character, and it may be used with profit in many 
cases instead of the soldering process now commonly employed. 

Solder cannot be used for joints which are ex])osed to con- 
tact with aci(l>. because most of the ordinary acids will dissolve 
the tin. of which the solder is in i)art com])osed. 

Tanks which are u.sed for the manufacture or storage of 
acids or acid salts, or for the storage of mineral oils, petroleiuu, 
etc.. are usually lined with lead. The joints in the^e linings. 
and in all of the lead pijies which are used for the same purpose, 
must be made b>- burning. 

The operation is performed by meltiug the edges to be joined 
a drop at a time, by means of a torch. It is essential that the 
flame which is used shall not oxidize or tarnish the metal. If 
the drop of melted metal does oxidize, it will not unite with 
the solid parts, and the joint will be a failure. 



GENERAL NOTES ON WELDING 



107 



The most certain and convenient way to secure a non-oxidiz- 
ing flame is to use hydrogen gas mixed with air to supplv the 
torch. Other methods may be employed, but none are so con- 
venient as the hydrogen gas process. 



A FEW EXAMPLES IX WELDIXG. 

In describing a few examples on w-elding. we will consider 
that the welder has acquired a knowledge in handling his torch 
and welding the various kind of materials, so this detail will be 
omitted, and the illustration confined to a description of the prep- 
aration incidental to the particular example. 

Welding a Crank Shaft: — The difficulties is welding a crank 
shaft as shown in I'igure 45. arc not in the performance of weld- 
ing; but in providing for exj^ansion and securing alignment, 
that will oljviate the necessitv of much machine work. 




Fifr. 4.') 
CRANK SHAFT ON Y P,I>()('KS I'l.MM'A 1." KD FOR WELDING 

Before assembling for welding the fracture is ground away 
to form a \' groove, as is usual in preparing any weld, but in 
this case there is about an eight of an inch of the fracture left 
undisturbed. This is to furnish a guide for adjusting the pieces. 
The shaft is then clamped in \' blocks like those shown in the 
picture. These \' blocks have a [)iece of cardboard or sheet 



ms 



OXV-ACETYLKXK WELDING AND CUTTING 



iron placed between the sloping- side of the block and the long V 
bar which holds them. In the picture above these pieces of 
sheet iron would be on the far side oi the two hl(K-ks shown to 
the left and on the near side of the block shown to the right 
and when the crank shaft is damped in position, they would 
cause an opening to sliow between the fractured ends of the 
crank shaft. This opening is to take care of expansion and 
should be about 1-32 of an inch. With the torch, the part sur- 
rounding the weld will be heated until this space is closed up by 
expansion, and then the \' shaped opening welded full. Before 
shrinkage takes place the clamps and strips of sheet metal are 
removed, wheii this part of the weld become rigid, the unwelded 
portion on the back is melted out and welded full. 

IVeldiui:; the Inner Wall of an .Into Cylinder: — .\ portion of 
the water jacket, outside the fracture, is cut out b\- drilling as 
shown in Figure 4^). 




Fig. 46 
AITO CYLINDHK' I'HKPAEED FOR WELDING 



The whole cylinder is then put into a preheating fire with the 
fractured side up and when suiTiciently heated the covering is 
laved aside and the fracture melted away with the torch and 



GP:XP]EAL NOTES OX WELDING 10{> 

welded full. The piece which was cut out of the water jacket 
is then welded back into place. For convenience in holding this 
piece in j)lace while it is being- fastened, a small rod may be 
welded in the center, to form a handle. 

\VELDI.\(; ATTO SPRIXC.^. 

The usual method in welding" auto springs, is to fi'^st bring; 
the spring to its normal jjosition and block it up with bricks 
to hold it in alignment while it is l)eing welded. Then with the 
oxy-acetylene torch the fracture is quickly melted and run to- 
gether. 

The process differs from welding mild steel in the fact that 
the edges of mild steel plates are separated a short distance to 
facilitate the flame entering between them, the space being filled 
with material melted from the welding rod; but when welding- 
springs, the edges are brought tight together and a narrow strip 
of the material adjoining the fracture is melted from the top 
down through to the bottom, adding only as nuich material 
from the welding rod as is required to restore the normal thick- 
ness. When this has been done on one side it is repeated on the 
other : but this time it is not necessary to weld as deep. 

The portion of the spring, which has just been welded, is a 
little softer than the rest and is not as liable to break from shock. 
It is not the custom to retemper this part of the spring for very 
good residts are obtained without. To make this part of the 
same temper as the rest, would require retempering the wiiole 
spring, which is an undertaking not to be recouimended to any 
one who is not skilled in that line and provided with a .suitable 
heating furnace and oil bath. Even then it is a treacherous job 
and better results are usually obtained by leaving the weld un 
tempered. 

It is well for the reader to refer to the illustrations on page 
I, 2, and 7 and note the temporary grates wbicb were con- 
structed to sustain the preheating fire. 



]]0 OXY-A^ETYL^^XE WELDING AND CT^TTIXG 

CHAPTER Xll. 

CUTTING IRON AND STEEL WITH THE OXYGEN JET. 

The rapid combustion of iron in oxygen has been known 
for over a century and was mentioned by I^avoisier. The chem- 
ical treatise on this subject mention that iron oxide formed is 
more fusible than the iron and is detached as the combustion 
]>roceeds. ccjntinually exposing' the bare iron to the attack of 
the oxygen. 

It is this phenomenon that makes possible the rapid cutting" 
of iron and steel, with a torch and oxygen jet. and although it 
has been known so long it was not until recent vears that the 
])rocess was used industrially. 

All thicknesses can be cut from the thinnest sheets to heavy 
armor plates for battle ships. The process is also being used 
extensively in steel foundries for cutting the gates and risers from 
steel castings. In fact the uses to which it may be advantage- 
ously applied are imuunerable. and as people become better 
acquainted with it. they are finding new uses for it. ( )n pages 
5 and 6 are mentioned a few of the recent applications of this 
process, to cutting the wreckage of ore-docks and sunken ships. 

YV/r Theory: — All instructions in autogenous welding cau- 
tion the operator to use a perfectly neutral flame, for if he uses 
too much oxygen, he is told, the metal will become oxidized, or 
burned up. If a small piece of iron, or steel is heated and drop- 
ped into oxygen it will burn rapidly. The iron actually be- 
comes a fuel and is burned in the oxygen ; and in burning it 
generates heat just the same as any other fuel would do in 
burning. This phen()menf>n which is so carefull\' avoided when 
making welds, is used to advantage in oxy-acetylene cutting. 
The torch is arranged to first deliver a hot neutral o.xy-acetylene 
flame until the metal is at a white heat, then a jet of oxygen is 
impinged against this hot metal and iron burning or oxidation 
ensues. 

The oxidation commences at the part which has previously 
been heated to redness, because at this temperature the reaction 
takes place more radiply. The combustion or burning of this 



CUTTING IKON AND STEEL WITH THE OXYGEN .lET 111 

portion of the iron, lil)erates heat, a portion of \vhich is ahsorbed 
by the surroundini;" iron, and raises it to a red heat, so that in 
turn it burns, lliis burning- is progressively extended by moving 
the torch along the line of the cut. 

This burned iron is known to chemists as oxide of iron and 
when first formed it may appear as a solid scale adhering to 
the surface of the iron. If it remain there it protects the iron 
against anv further oxidation or burning just the same as a thick 
covering of ashes will sto]) the burning of wood. W'nvught iron 
and mild steel, melts at a luuch higher temperature than does 
the oxide of iron. So on these substances the oxide will melt 
first and run off leaving the surface of the metal clean, and con- 
tinually exi)osed to the attacks of the oxygen jet. 

The oxide on cast iron cannot be melted off to expose the 
clean surface to the attack of the oxygen jet, because its melting 
temi)erature is higher than that of the metal. It may be melted, 
but the metal melts first and the oxide mixes with it. The proc- 
ess is not the clean rai)id cutting action obtained with mild 
steel, or wrought iron, but is merely one of melting. It is there- 
fore said that cast iron cannot be cut by the oxy-acetylene proc- 
ess. This is also true of coi)])er. brass, bronzes, aluminum, and 
ver\ high carbon steel. 

Using the TorcJi : — In using the oxy-acetylene cutting torch 
it is advisable to first adjust the regulator on the oxygen drum 
to deliver oxygen at fo to 50 pounds pressure, according to thick- 
ness of the metal. Then turn on a little acetylene, ignite it, and 
open the needle valve in the b.-uidle of the torch until the base 
of the flame appears to leave the torch and stands away about 
an eighth of an inch. The acetylene flame is now a large, flar- 
ing, smokv. irregular shaped mas>, but open the little needle 
valve that controls the oxygen supply and the flame will com- 
mence to assume definite size and proportion. C'ontinue to slowly 
open this valve and there will ajjpear an inner white flame that 
blends with a thin feathery edge into a pale blue outer flame, 
and as the owgen sui)ply is slowly increased this inner white 
flame becomes smaller, and the outline more distinct. When 
the thin featlierv outline of this inner flame is cntirelv gone and 



112 OXY-ACKTYLENE AVELDING AND CT'TTINO 

the dividing" line between the two parts of the tlanie is distinct. 
the oxyg-en supply is sufficient, and the flame is neutral. 

To start the cutting action, the little white inner flame should 
he held about three sixteenths of an inch from the metal until it 
begins to melt, then the thumb lever is ju'essed which starts a flow 
of oxygen through the cutting tip. \Mien the oxygen comes in 
contact with the metal it hums it very rapidly, and oxide of iron 
runs or is blown otit of the cut. When starting a cut in the middle 
of a plate of steel, there is no place for this melted iron oxide 
to run out. so it gathers in a little puddle where the force of the 
torch blows and spatters it. In this event care should be taken to 
prevent it splashing into the end of the torch. This may be pre- 
vented by holding the torch a little farther away from the plate 
than would be necessary in starting the cut at the edge. 

After the cut is started and there is a place for the iron oxide 
to escape, the torch may be brought a little closer to the work and 
steadily advanced without wabbling or tilting, moving evenly 
along the line of cut as fast as the metal will burn and run out. 
If the torch is held too far away, the action is slower and the g-ap 
of the cut is wider, while if it is too close, particles of burned iron 
may enter the torch. A jerky, wabbly movement makes a ragged 
cut. Plates, ys or 3-16 inches thick, can be cut with the ordinary 
welding torch, by first heating the metal to a white heat with the 
oxy-acet\lene flame and then shutting the acetylene entirely off 
and using the oxygen jet the same as in the regular cutting torch. 
The heat of the burning steel is sufficient t(^ cause the combus- 
tion of the adjoining material and thus the operation is contin- 
uous without the use of the preheating flame which accompanies 
the cutting torch. 

The jerky wabbly movement, previously mentioned, not onl\ 
makes a ragged cut. but it retards the progress of the cut and 
adds to the cost of the operation. In consequence of this, there 
have been cutting" machines designed, which carry the torch at 
any desired angle and at a uniform speed across the work. To 
obtain the best results some arrangement of this kind is required. 

In figure No. 47 is shown a machine of the kind just described, 
which is designed to cut bars or structural shapes. The piece 
to be cut is clamped in the \' shaped notch, and the cutting torch. 



CUTTING I HON AND 8TKEL WJTH THE OXYGEN JET 113 

wliich is easily discernahle in tlie picture, is carried steadily 
across tlie work by means of a screw. 

A simple device for cutting- elliptical man holes in boiler 
plates, may be made by providing- a track, of angle iron, formed 
to the shape of the desired manhole and ecpiipped with a carriage 
t(^ carrv the torch. The carriage can be of the easiest construc- 
tion, and ])r(n-ided with three wheels, two of which will ride on 
the track and one on the ]ilate. 




i.t:. 4 7 
MACHINE \-\)U ClT'l'ING P..\lx'.'^ .WD STK'r( "rC K.\ L SHAPKS 



The machine shown in ihc following tigure Xo. 4S is designed 
for cutting circular plates or holes. The heavy base which serves 
as a center, is held in ])lace by its weight, and affording a hear- 
ing for the upright stud which carries the horizontal bar. The 
bar slides through the stud and may be clam])ed in any position 
that will ijive the retiuired diameter to the circle. After this ad- 



J 14 



OA^-A('KTVI.KM-: WKLDINU AM) CUTTlN(i 



iustmenl has l)een made, the stud is rotated in the ba>e. by hand. 
carrviniL^' the torch anmnd in the ])ath of a circle. The torch 
shown in tliese two ilhistrations i> es])eciall\- designed for nia- 
clhne nse. 




MA( I1IM-: FOi; (TTTlNd ( 'I KCl ' l.A i; I'l.ATKS AND OI'KN I .\(JS 

Structural iron workers, erecting" contractors, and others en- 
gaged in building or tearing down old structures, find the oxygen 
cutting ])rocess of great service to them. The saving which re- 
sults fn)m its use may be judged by the reader, after noting the 
table of cutting speeds and costs as noted below. 



Thickness 


Cost of gas 


C(t. 


2c per foot 


T 


inie per 


of 


( )xygen 




.\cetvlene 


foot 


])late 








in 


seconds 


■4 


$0.0082 


i 


$0.0026 




24 


/ - 


i 0.0154 




0.0034 ; 




30 


I 


1 0.0244 


1 


0.0042 




38 


1/2 


0.030^) 




0.0066 




4'> 



CITTIXC IRON AXi) STK1-:L WITH THE OXVGKN .HOT ] i: 




Cl'TTINC OLD STi:i;i, I'LOOK' I'.KA.MS 



Durinq- the year 1914 the old union depot in MiiineapoHs was 
torn down to make room tor a new l)uil(lin^". 

All tile structural steel ineiubers in this buildinjn' were reniovetl 
by cutting- them free, with the oxy-acetylene cuttinq- torch. The 
above picture was made from a photo, of the cutters, while at 
work. The process was eminently successful and showed a ij^reat 
savinj^ over the old method of removing them by knocking- off the 
rivet heads, or sawiu"-. 



llf) 



ox Y- ACETYLENE WELDING AND CUTTING 




Fi<i-. 5n 
REDITC1\(; AX OLD liOILKlJ TO SC HAP 



It was recently required to remove an (tld steam boiler from 
the snb-basement of a department store. The boiler had been 
in use many years, during: which time the building- had been re- 
modeled and brick walls built, in a way that required their de- 
struction to remove the boiler in one piece. With the oxy-acety- 
lene cutting torch the lx)iler was quickly reduced to scrap and re- 
moved in pieces. 



CUTTING TROX AND STEEL WITH THE OXYGEN .lET 117 




Fig. 51 
REDI'CIXG AN OLD BOILIIH TO SCILVI' 



118 OXY-ACETYLENE WELDING AND CUTTING 

CHAPTER XIII. 

BOILER MAKING AND SHEET METAL WORK. 

There is perhaps no class of wnvk where the ox\-acetylene 
cutting" and weldin.Li" processes can he used to better or as "ood 
advantage as in boiler and sheet metal work. 

Boiler makers who consented to give the i)rocess a trial in 
their shops, were snrprised and marveled at the savings they 
could realize by its continual use. Even then they had not learned 
of all the api)lications. of wliich this a])paratus was capable, and 
every dav they are linding new places where the ])rocess can 
save them time and money. 

A Su]KM-intendent. of Motive Power, on one of our promi- 
nent railroads, recently made the statement that the oxy-acetylene 
plant in his shops, was saving for his company, an average of 
four dollars an hour, for every hour a torch is in use. The 
torch has such universal application, and the operations to which 
it can be advantageously applied, are so general and fre(|uent. 
thev can hardiv be enumerated : but as the welder 1)ecomes familiar 
with the process he finds them himself. 

To su.stain these statements, we will cite a few instances 
where the (i])erati<)n ])r(ivc(l ils su])cri()rily over old methods. 

Cutting a full door jiatch for a locomotive boiler, usually re- 
quired 6 hours time for a boiler maker, ami his helper, at an 
average total cost of $4.04. The same jt^b done by the oxy- 
acetylene process, required nine minutes time and cost 25 cents 
for labor and gas. 

Cutting a side sheet and door sheet by the old method, re- 
quired 18 hours time of two men and usually cost $12.15. P>y 
the new method, the same work was done in thirty minutes at 
a cost of (S3 cents. 

Another incident is in welding an outside sheet. On previous 
occasions it re(|uire(l the work of two men for \f> hours and 
cost $10.80 to make the repair, which was welded with an oxy- 
acetvlene torch in 3 hours time at a total cost of $5.85. 

A cracked sheet, usually required patching and to do this 
at an average cost of $15.00 was good work; l)ut with the oxy- 



HOILKR MAKING AND SHKKT ^fKTAL WORK 11!< 

acetylene process, the crack can be welded and the sheet made 
as good as new, at a cost of $4.00. The welded crack has an 
advantage over the patch, in the fact that it only ])resents one 
thickness of metal, to the action of the tire. This advantage is 
well appreciated h\' boiler makers. 

To rednce an old boiler to commercial scrap, recjuired the 
labor of two men for 80 honrs and usually cost about $40.00. 
The same work can be done with one man using the oxy-acetylene 
torch in 73'j hours and will cost, for labor and gas. about $12.00. 

The question will probably occur to some ])ractical boiler 
makers, whether an o.w -acetylene welded seam will withstand 
the action of fire. In answer to this we will cite an inciilent. 
m Duluth. where it was desired to coustruct a bosh jacket, tor 
one of the large blast furnaces being built there at that time. 
It was particularly desired to get a smooth seam, so that the 
cooling water would stay on the jacket, better than was possible 
for a film of water to do on such a surface when broken by 
seams and rivets, and al^o to ha\e only one thickness of metal, 
to eliminate the great lial)ilit\- of burning, due to double thick- 
ness. 

The bosh jacket was in the form of a truncated cone, aiul 
was eleven feet in diameter at the bottom, si.xteen feet at the 
top, nine feet high, and made of half inch sti»ck throughout. 

In fabricating this job it was Iniilt in four sections or seg- 
ments aufl welded along the vertical joints, with an oxv-acetvlene 
torch. When the welds were fmished the joints were ground 
smooth and were hardlv percei)tible. The job was eminentK- 
satisfactory and in several years of continuous >er\ice. has shown 
nc) indication of weakening at the welded joints. 

Welding Pieces of Piffrrciit Tlilchiicss : — ( )xy-acetylene weld- 
ing is not easilv applied to ])ieces of dit'lerent thickness, because 
the melting of the two edges is not equal, and does not take 
jilace at the same time, .^ince the torch is too powerfid lor the 
thin ])iecc or too weak for the thick |)iece. A clever welder. 
however, can manage his torch so that the heat given to the 
two edges is proportional to their thickness; but if the differ- 
ence is verv great, the joint is not easily obtained. 



120 



OXY-AOETYLEXK WP^LDING AND CTTTINO 



Effects of lixpansioii : — The effects of expansion often act 
in such manner that the edges to be poined separate and approach 
each other alternately. If one wishes to join two plates by auto- 
genous welding, and the edges have been arranged parallel, when 
the weld has commenced one first observes a widening of the 
space, at the other end of the plate. See figure 5^^ It the weld- 
ing is continued, the (levialii)n (|uickly stops and the opposite 
movement takes place, that is. the edges ap])roach, and as the 
weld advances they will overlap each other. See figure 54. 




rig. 66. 
FABRICATING A BOSH JACKET IN SHOPS AT DULUTH, MINN. 



BOILER MAKING AND SHEET METAL WORK 



I'Jl 




Fig. 52 Fig. -).■; Fig. .■)4 

EXAMPLES OF EXPANSION 

To overcome this final overlaping, two methods may be fol- 
lowed : one is to separate the edges before commencing' to weld, 
as shown in figure 55, and the other to weld in spots about a 
foot apart, throughout the length of the joint. This latter 
method is called tacking. 

In the first case the initial separation should be about 1-20 
of the length of the weld, and as the weld progresses the space 
at the far end may be allowed to close a small amount, thus con- 
tinue closing the space as the weld advances, at a ratio that will 
bring the edges together when the weld reaches the end. In 
starting- this job the edges will first be placed parallel until a 
few inches are welded and then they will be sprung oi)cn, as sug- 
gested. 




Fig. 55 

METHOD OP OVERCOMING EFFECTS OF EXPANSION, WHILE 
WELDING PARALLEL EDGES 



122 



OXV-ACKTYLEXK WELDING AND CT^TTIXG 



If the system of tacking is used, the expansion cannot act 
laterally, as in the previous case, and this causes a deformation 
as shown in figure ^(i. In the majority of cases, it is easy to 
!)'ring the plates hack to the original ])osition. 




Fij 



.")() 



I )i: FORM ATI ON CArHKI) BY KXI'ANSlON WHKN TIIK JOINT HAS 
BEKN i'HI-:VTOrsLV TACKKD 



'flic Freparalion of Joints: — Welding very thin pieces, is 
especially difficult on account of the great liahility of melting 
holes through the material. In thi> kind of work, the method 
of overlapping the edges as shown in figure 57 is very faulty. The 
best method l)eing to bend the edges up as shown in figure 5S. 
These u])turned edges are melted down and furnish welding 
material. 

If the plates are thick enough to permit hexeling tlie\- may 
be prepared as in iigures so and ()0. This i> explained f|uite 
thoroughly under "( ieneral Notes on Welding." 

In Joining ])lates at right angles, the groove for welding is 
obtained without beveling, b\' sim])ly arranging as shown in 
figure 62. 

The joint in figure 61, which is not beveled at all. is bad 
when the plates are over ^ of an inch thick, because the amount 
of penetration is doubtful. The arrangement shown in figure 
63 is favorable from the view point of penetration, but the weld 
is difficidt to make and in figure 04 the diiTercnce in thickness 
between the beveled side and the unbeveled side, makes the joli 
difficult for the reason that the heavy ])art re(|uires more heat 
than the other; but the joint can be successfully made by skillfid 
manipulation. 



BOILKR MAKING AND SHEET METAL WORK 1: 




Ely. .-,7 

/' 

f 



Fill. 5;» 



Fii:. (id 




Vv' (il 




Fiu. <i 



Fi-r. ()•■! Ei-. (i4 

(iOOD AM) l^AD KXAMPr.KS OF I'K' FI'A Iv' I'M) JOINTS 



124 OXY- ACETYLENE WELDING AND CUTTING 

Welding a Crack in a Boiler Sheet: — It is very exasperating 
and sometimes embarrassing to the welder, to nicely finish a 
weld in a cracked plate, and then stand back and see it reopen 
and grow a few inches longer, when the sheet cools off. This 
is sure to happen unless some provision is made to take care 
of the expansion. 

A careful study of this phenomenon will be of benefit, and 
when the principle is understood it will help to solve other dif- 
ficulties which will occur in boiler work. 

When the metal around the crack is brought to a welding 
heat, it becomes soft and incapable of resisting compression, 
consequently, the expansion caused by the heat, pushes the soft 
metal together, so that when it cools off it icoiild be shorter than 
it was before ; but to shorten is impossible, because it is a part 
of a cold, solid, uncompromising plate. The tension thus caused 
by the shrinkage is enormous. 

If the weld was strong enough to hold, it would ])roduce 
strains in the rest of the boiler and would be objectionable. 

To successfully weld a crack of this kind, it is only necessary 
to relieve the sheet of the strains resulting from shrinkage, and 
this may be done by preheating an extensive portion of the plate, 
at each end of the fracture, and keep it hot during the whole 
performance of welding. 

Preheating in this way will cause the fracture to open and 
when the welder can clearly see the opening, he can apply his 
process to the weld and finish as in welding any other plate. 
Then when the wdiole area cools it will resume its normal posi- 
tion and be void of strains or the liability to crack. 

After reading the preceding pages of this book, the welder 
should not need cautioning, to be sure and weld deep through to 
the other side of the plate. 

Welding in a Patch : — In welding in a patch, the effects of 
expansion and contraction can be overcome without preheating. 
This is done by "dishing" the patch. 

Cut the patch a little bigger than the hole and then "dish" 
it until the outside edges just fill the opening. After bevel- 
ing the edges of the hole and patch, it is inserted in the 
opening with the convex side out, and tacked in several places to 



BOILKK ^[AKING AND SHEET METAL WOKK 125 

secure it. Finish the weld as instructed in previous paragraphs 
and when shrinkage ensues, the convex patch is flattened down 
with a hammer. Flattening the patch enlarges it and compensates 
for the shrinkage. 

IVeldbii:: Flues: — The oxy-acetylenc torch can be used very 
successful for re-tipping Rues. By the old method flues and tips 
were scarfed, brought to a welding heat in the blacksmith forge 
and then welded by means of hammer blows. To do this work 
properly it would therefore require the services of an experienced 
blacksinith and in comparison to the new method takes consi- 
derable longer. Flues can best be re-tipped by means of the 
oxv-acetylene torch by tirst grinding the ends of the tine and 
tip to a bevel edge, butting the beveled ends together and weld- 
ing them in place. Care must be taken not to allow the metal to 
flow through and leave a rough edge on the inside. Should this 
occur, the end of the flue could be slipped over a piece of round 
shafting to be used as a mandrel, and hammered smooth. \'ery 
little extra metal shotild be added on the outside otherwise the 
flue would not pass through the flue sheet. 

Where a comparatively pure supply of water is available, it 
has been found practicable to weld the flues directly to the flue 
sheets. When they are so welded, it is of course difficult to take 
them out and hence this methcMl is not recommended where it 
is necessary to frequently remove the flues. 

In welding new flues to the flue sheet, they should be welded 
on one end only, the other end being rolled. The welding should 
be done first leaving the other end free to take care of the ex- 
pansion and contraction. The flue should be allowed to extend 
through the flue sheet about one-eighth inch or three-sixteenths 
inch and then welded around between the end of the flue and 
the sheet. 



126 OXY-ACETYLENE WELDING AND CUTTING 

CHAPTER XT\'. 

CARBON BURNING. 

Carl)on is a fuel. It is the carbon in coal that burns and gives 
lis heat by cheniicallv uniting' with oxygen to form carbon 
dioxide as explained on page 17. Soot is carbon which has 
been liberated by heat, and for lack of oxygen was not consumed. 
If soot can be heated in the ])resence of oxygen it will burn and 
leave no ashes, but if the oxygen is derived from the air this is 
<li(ficult to accomplish because the ])redominance of nitrogen, in 
the air. absorbs the heat of reaction, lowering the temperature 
below the point at which the carbon will burn. When ])ure 
oxygen is used, the burden of nitrogen is avoided and the carbon 
will burn rapidly. 

Soot or cari)on fre(|uently accumulates in the com])ression 
chamber of internal combustion engines, to such an extent that 
it interferes with its perfect working. 

In the past, it has been the ])ractice of mechanics to remove 
this carbon by scraping. The operation re(|uired considerable 
time and was (|uite an expense; but since the advent of cheap 
oxygen, this carbon is Ixjing removed by burning it. 

The process consists of starting combustion with a little 
kerosene, which is s])rinkled into the cvlinder. ignited and im- 
mediately followed with a stream of ox\gen. i he carbon Hashes 
into a tlame and as long as it is fed with oxygen it burns to the 
last trace. 

liy this method a four c\linder motor can be cleaned in twenty 
minutes, at a ver}- trifling expense. 

Dirrctiois for a Carbon Burner: — Have the ])iston at the top 
of the compression stroke, and remove the spark plug and valve 
caj). Then sprinkle al)out half a tablespoon of kerosene into the 
valve chamber, and cylinder head. After is has soaked into the 
carbon, light it and immediatelx insert the long" slender nozzle 
of the torch. When the oxy.gen comes in contact with the car- 
bon it will burst into flames and dm-ing the earlier i)arl of the 
process, these flames will rush from all the o])enings. l"or this 
reason it is advisable to keep the face away from the work. 



CARBON iui;.\ix<; 



127 



When the carbon diminishes the tlame will be replaced Ijy 
sparks and the How of «;as shonld be increased, to make it hnnt 
all the little corners. This may be assisted by thrusting- the torch 
around into ditlerent ])arts. 

If the flame i^oes out suddenly. i)Ut in more kerosene and re- 
li;j;-ht it. This may have to be rei)eate(l several times. After the 
cvlinder i> cleaned, blow all the loose particles t)Ul with com- 
pressed air. 

Cleaning- cvlinders in this way does not heat them to a-^ high 
a temperature as tlie\- attain in service. 




CARBON Bl'K'NKIv' .XT WO UK 



12.S 



OXY-ACETYLEXE WELDIXG AXD CUTTING 



x; 



Total 
Cost of 

cut 
per foot 


$0.0126 
0.0213 
0.0322 
0.041 


o 

o 

X 


Amount 

@ 40c 

per hour 


$0.0026 
0.0033 
0.0042 
0.005 


Time per 
foot in 
seconds 


-r c 00 ic 
cj cc re -^ji 


Total 

cost of 

gases 


.$0.01 
0.018 
0.028 
0.036 


X 

Oi 

x 

=H 

O 

-u 

CO 

O 
O 


< 


CI CI r^t L- 

c; C' c; c 
o c; o c 
o d c c: 


Oxygen 

@ 2c 
per ft. 


$0.0082 
0.0154 
0.0244 
0.0306 


Thickness 
of 

plate 
in inches 


'^ " -, ^' 






Total 

Cost of 

Weld 
per foot 


Ttl l^ L- Ol -^ 

o ■-;-*«> CI 


o 
=(- 

X 

O 


Amount 

(S) 40c 

per hour 


CJ «o 

CJ »o O CC o 

O O i-H >-^ CI 

-=&"■■■ 


Time per 
foot in 
minutes 


.3.33 

8.57 
15. 
20. 
30. 


Total 

cost of 

gases 


CC rH 

CI c<j lo ?o -^ 

C .— 1 CO IC o 

e c d d ^ 


X 
X 

it 

o 

X 


-^ -^. ^ 


r-i l-O 50 to Oi 
O O r-S C^_ Tj- 

d d d d d 


rai 2c 
per ft. 


$0,012 
0.065 
0.19 
0.30 
0.55 


Thickness 

of 

plate 

ill inches 


::^:j??^;|?:;^ 



USEFUL INFOEMATION 



129 



TABLE XII 

QUANTITY OF GAS IN CYLINDERS 

Under Varying Pressures and Constant Temperatures 
Rated capacity and pressure of druni) at 68 o Fahrenheit 



100 Cub 


c Feet a"t 


100 Cubic Feet at 


200 Cub 


c Feet at 


300 Lhs 


Pressure. 


1800 Lbs 


Pressure. 


1800 Lbs 


Pressure 


Varyinf 


Quantity 


Varying 


Quaiititv 


Varying 


Quantit \ 


Press'ii-es. 


in Cu. Ft 


Pressures. 


in Cu Ft 


Pressures. 


in Cu. Ft 


300 


100 


1800 


•100 


1800 


200 


270 


90 


1620 


90 


Ui20 


ISO 


240 


80 


1440 


80 


1440 


160 


210 


70 


1260 


70 


1260 


140 


180 


60 


1080 


60 


1080 


120 


150 


50 


900 


.50 


900 


100 


120 


40 


700 


39 


700 


78 


100 


33 


500 


28 


500 


56 


75 


25 


300 


17 


300 


33 


50 


17 


100 


6 


100 


11 


25 


8 


18 


1 


18 


2 


3 


1 


9 


: 


9 


1 



TABLE XIII 

VARIATION OF PRESSURE IN CYLINDERS 

I'Tider Varyinji Temperatures and C'onstant Quantity 



Temperature 
Fahrenheit. 



120 

100 

80 

60 

40 

20 



—10 

-20 





Initial Pressure at 68° 


F. 




100 Lbs 


300 Lb>. 


ISOO Lbs 


109.85 


329 5 


1973 




106 05 


318 2 


1909 




102 3 


306 S 


1841 




98 48 


295 5 


1773 




95 7 


284 1 


1705 




90 91 


272 7 


1636 




87.12 


261 4 


1568 




85.23 


255 7 


1534 




83 33 


250 


1500 





130 



USEFUL INFORMATION 



TABLE XIV 
COMPARISON OF DEGREES CENTIGRADE AND FAHRENHEIT. 



-Below Zero. 


Above Zero. 


Above Zero 


Equivalents. 


C F 


C F 


C F 


C F 


200 — 328 


525 - 977 


1250 — 2282 


1—18 


150 — 238 


550 — 1022 


1275 — 2327 


2 — 3.6 


100 — 148 


575 — 1067 


1300 — 2372 


3 — 5.4 


50 — 58 


600 - 1112 


1325 — 2417 


4—72 




625 — 1157 
650 — 1202 


1350 — 2462 
1375 — 2507 


5 — 9 

6 — 10 S 


Above Zero 


C F 


675 — 1247 


1400 — 2552 


7 — 12 6 


— 32 


700 — 1292 


1425 — 2597 


8 — 14 4 


25 — 77 


725 — 1337 


1450 — 2642 


9 — 16 2 


50 - 122 


750 — 1382 


1475 - 2687 


10 — 18 


75 — 167 


775 — 1427 


loOQ — 2732 


11 - 19 S 


100 — 212 


800 — 1472 


1525 — 2777 


12 - 21 6 


125 — 257 


825 — 1517 


1.550 — 2822 


13 - 23 4 


150 — 302 


850 - 1562 


, 1575 — 2867 


14 — 25.2 


175 — 347 


875 — 1627 


! 1600 — 2912 


15 — 27.0 


200 — 392 


900 — 1652 


1 1625 - - 2957 


16 - 28 8 


225 — 437 


925 — 1697 


1650 — 3002 


17-30 6 


250 - 482 


950 — 1742 


i 1675 — 3047 


IS - .32 4 


275 -- 527 


1000 - 1832 


1700 ~ 3092 


19 !— 34 2 


300 — .572 


1025 — 1877 


1725 — 3137 


20 - 36 


325 — 617 


1050 — 1922 


1750 — 3182 


21 - 37,8 


350 — 662 


1075 — 1967 


1775 — 3227 


22 - 39.6 


375 - 707 


1100 — 2012 


1800 - 3272 


J3 — 41 4 


400 — 752 


1125 -- 2057 


1825 — 3317 


24 — 43 2 


425 - 797 


1150 — 2102 


18.50 — 3362 


25 — 45 


450 - 842 


1175 — 2147 


1875 — 3407 




475 — 887 


1200 — 2192 


1900 — 34.52 




500 — 932 


1225 — 2237 


2000 — 3632 





TABLE X\' 
WEIGHT OF OXYGEN GAS DRUMS 



Oxygen. 


Capacity. 


Pressure 


Weight 


Low Pressure. 
High Pressure. 
HigU Pressure.. 


100 cub ft. 
100 cub ft. 
200 cub ft. ■ 


300 lbs. 
1800 lbs. 
1800 lbs. 


150 lbs. 
125 lbs. 
150 lbs. 



USEFUL INFORMATION 



131 






'fa.S 






^ b-Jm 05 Ch 



0-5 ^ 3 






>, o 1:1. 



0'-ic<>cor^coroioa)'-i 
o o o o o -- ■>) ^'s 00 -H 



X M rc -M -^ £■ '~ 
-r >:<— -M r- r- rr -t _ 



;^ If^ lO M^ CO 



X f. ^. 

-^ O K 



x 



02 
CO 

o 
o 

I— I 
E-i 

% 

OQ 

o 

o 















^ ^ „ rt ^ ^1 ~) '.0 -^ -r C2 (M 



— ' (M ^■^ •* 'O to t^ X w5 o ^ OJ 



132 



INDEX 



Atomic theory 13 

Atomic weights 12 

Acetylene 23 

Alloys -...- 41 

Alloys — table of _ 42 

Aluminum 43 

Acetylene generators 44 

Assembling cutting torch 56 

Automatic Oxygen regulator 59 

Acetylene Regulator 58 

Acetylene — oxygen required to 

consume 50 

Acetylene in drums 81 

Acetone 8 1 

Adjusting the flame 95 

Aluminum welding 105 

Air — oxygen from 19 

B 

Building in gear teeth 4 

Boyles Law 25 

British thermal unit 31 

Blister Process 39 

Brass 40 

Brass— welding 1 04 

Building a furnace 76 

Beveling 89 

B ronze — welding 1 04 

Boiler making 1 18 



Calcium Carbide 21 

Calorie 3 1 

Centigrade 32 

Coefficients of expansion 33 

Calculations in expansion 33 

Conductivity of heat 34 

Cast iron 35 

Cast iron welding IQl 

Cast iron flux 88 

Copper 39 

Copper flux 88 

Copper welding 104 

Carbide 21 

Carbide to water generator 45 

Carbide — yield of gas 

Composition of sludge 72 

Cost of acetylene 69 

Clean oxygen hose 80 

Cleaning the weld 89 

Charges for welding service 84 
Chloride of potash method of pro- 
ducing oxygen 18 

Cutting torch 53 

Cutting iron and steel 110 

Cutting steel floor beams 115 

Cutting machines 1 13 

Cost of gas for cutting 114 

Carbon burning 126 



Comparative cost of cutting 7 

Chemistry 1 1 

Origin I I 

Elements 1 1 

Symbols 1 1 

Atomic weights 12 

Notation 12 

Affinity 1 3 

Atomic theory 13 

Valence 14 

Re-action 16 

Combustion 16 

Flame 1 6 



Drip type generator 45 

Dissolved acetylene 81 

Defects of welds 100 

Directions for carbon burning ...126 
Drums of acetylene 81 



Examples of savings 4 

Elements 1 1 

Electrolysis 1 9 

Effect of temperature on pressure 28 
Expansion 32 



INDEX 



133 



Expansion — coefficients of 33 

Expansion — calculating the 33 

Expansion — precautions regarding... 91 
Expansion — effects of 92-120-121 

Economy of preheating 94 

Examples in welding 107 



Flame 16 

Fahrenheit 3 1 

Ferrous group of metals 35 

Flashing Back 50-80 

Fluxes 87 

For cast iron 88 

For copper 88 

Filling in holes 99 

Fabricating a bosh jacket 119 



Oxygen 17 

Hydrogen 20 

Nitrogen 21 

Acetylene 23 

21 

26 
23 

27 
89 



Gas — weight of 

Gas — quantity in drums 

Gas — yield from carbide 

Gay Lusac's Law 

General notes on welciing 



H 

Hydrogen 20 

High pressure pump 29 

Heat 30 

Heat conductivity 34 

Heat liberated by carbide in wa- 

ter 44 

High pressure torch 52 

How and where to preheat 95 

Handling the torch 96 

Holes— filling in 99 



L 

Low pressure torch 51 

Loss of pressure in pipes 70 

Loss of pressure in valves and fit- 
tings 71 

Leaks in oxygen pipes 73 

Lead burning 106 

Leaks — testing for 73 

Lead welding 106 

Liquid air — oxygen from 19 

M 

Metals and their properties 35 

Malleable cast iron 36 

Malleable cast iron welding 102 

Melting temperatures „ 39 

Movements of the torch 98 

Machine for cutting 113 

Manganese dioxide method of pro- 
ducing oxygen 18 

N 

Nitrogen 21 

Neutral flame 95 

o 

Oxygen 1 7 

From air 19 

By electrolysis 19 

From chloride of potash and 

manganese-dioxide 18 

Oxyacetylene cutting 6 

Oxyacelylene torch 50 

Oxygen required to consume acety- 
lene 5 
Operating plants 68 

P 

Phases of combustion 1 7 

Physics 25 

Phneumatics 25 

Pressure regulators 58 



134 



INDEX 



P 

Preheating furnaces 76 

Protecting apparatus _ 77 

Portable acetylene drum plant 81 

Portable acetylene generator plant 83 
Preheating to eliminate defects 94 

Preheating how and where 95 

Puddle-system ' 05 

Preparing the joint 1 .^-^ 

Propagation of flame 5U 

R 

Repairing locomotive cylinder 2-3 

Repairing pump case 10 

Reaction 1 

s 

Steel 38 

Steel welding 101 

Selecting a generator 47 

Sludge — composition of 72 

Scrapping a boiler iio 



T 



Time required to cut plates 7 

Temperature 3 1 

Thermometers 3 1 

Temperature of melting 39 

Thermite 43 

Typical carbide to water genera- 
tor 45 

Torches 50 

Torches — for machines 57 

Testing pipe lines 73 

Time card for welding shop 86 

Theory of cutting 110 



U 

Use of the oxyacelylene torch 4 

Using the cutting torch Ill 

Unit of heat .....31 

Unit — British thermal 31 

V 

Valence 1 4 

Velocity of propagation of flame 50 
Vulcan automatic acetylene gene- 
rator 61 

Vulcan portable generator plant . 67 

W 

Welding crank shaft 8-107 

Weight of gases 21 

Wrought iron 37 

Welding — 

Iron and steel lOl 

Cast iron 101 

Malleable cast iron 102 

Copper 1 04 

Brass 1 04 

Bronze 104 

Aluminum 1 05 

Lead 106 

Welding rods and fluxes 87 

Welding table 74 

Welding — examples in 107 

Auto cylinders 108 

Auto springs 1 09 

Crack in boiler 124 

Patch in boiler 124 

Flues in boiler 125 

Welciing pieces of different thick- 
ness 1 19 



Yield of gas from carbide 23 



Pure Calcium Carbide 

"HPHE purity of Acetylene goes hand in hand with 
the purity of Carbide, and, just as preventive is 
better than cure, so to use only an excellent quality of 
Carbide, thus avoiding impurities, is clearly better than 
to use a poorer grade which is sure to result in the 
formation of impurities." 

—PROF. GEORGE GILBERT POND, 

Leading Authority on Acetylene. 

We thoroughly agree with Professor Pond, that only Car- 
bide of the Greatest Purity should be made. Therefore, we 
handle only the one grade — that the best it is possible to 
produce. Our 

r 
TRADE f "^U^^VVS^^M;^' MARK 




distinguishes pure from impure Carbide, and stands for a defi- 
nite, guaranteed gas yield. 

American Carbolite Sales Co. 

DISTRIBUTORS 
Warehouses Everywhere DULUTH, MINNESOTA 



S*^'^'^'''^'""'^''''^''''"''^'""'^'^'"^^'''"'^^ 



A Vulcan 



Welding Torch, Acety- 
lene Generator, or Com- 
plete Welding Plant is 
far in advance of the 
average Welding appa- 
ratus. All SPECIAL 
FEATURES are pro- 
tected by patents. Cost 
is lowest consistent 
with greatest efficiency 
known. 

VULCAN PROCESS CO. 

Factory and Sales Room 25 th and University Ave. S. E. 

MINNEAPOLIS, MINN. 



1^ 



Pure Compressed 
Electrolytic Oxygen 
Highest Grade Vulcan 

Oxy - Acetylene 
Welding Supplies 

llicre arc some cheap iniilalions of N'ulcan Wcldin;; 
supplies. Do not accept them. If your dealer does 
not carrv \ulcaii supplies, send order tlirect to us, and 
we will make shipment same day order is received. All 
our weidinj; rods, includini;- the cast iron, steel, bronze, 
aluminum and aluminum solder, rods are made u]) alter 
our own f(»rmulaes. and have been ado])led only alter 
years of ex])erimentini;- and testin,<;. ( )ur duxes fi>r 
cast iron ueldin.u-. aluminum weldin-- or brass and bronze 
weldini;- are extra stren,L;th and when usin.^ ibem. direc 
tions should he followed clt'sel). 

We maintain a complete j >1) repaii plant in connec- 
tion. 

NORTHERN WELDING COMPANY 

Manufacturers of 
Complete Weldin-- iM|uii)ment and Supi^Hcs 

25th and University Ave. S. E. Minneapolis, Minn. | 



